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    <a href="https://codemirror.net"><h1>CodeMirror</h1><img id=logo src="logo.png"></a>
    <ul>
        <li><a href="../index.html">Home</a></li>
        <li><a class=active data-default="true" href="#overview">Manual</a></li>
        <li><a href="https://github.com/codemirror/codemirror">Code</a></li>
    </ul>
    <ul>
        <li><a href="#usage">Basic Usage</a></li>
        <li><a href="#config">Configuration</a></li>
        <li><a href="#events">Events</a></li>
        <li><a href="#keymaps">Key maps</a></li>
        <li><a href="#commands">Commands</a></li>
        <li><a href="#styling">Customized Styling</a></li>
        <li><a href="#api">Programming API</a>
            <ul>
                <li><a href="#api_constructor">Constructor</a></li>
                <li><a href="#api_content">Content manipulation</a></li>
                <li><a href="#api_selection">Selection</a></li>
                <li><a href="#api_configuration">Configuration</a></li>
                <li><a href="#api_doc">Document management</a></li>
                <li><a href="#api_history">History</a></li>
                <li><a href="#api_marker">Text-marking</a></li>
                <li><a href="#api_decoration">Widget, gutter, and decoration</a></li>
                <li><a href="#api_sizing">Sizing, scrolling, and positioning</a></li>
                <li><a href="#api_mode">Mode, state, and tokens</a></li>
                <li><a href="#api_misc">Miscellaneous methods</a></li>
                <li><a href="#api_static">Static properties</a></li>
            </ul>
        </li>
        <li><a href="#addons">Addons</a></li>
        <li><a href="#modeapi">Writing CodeMirror Modes</a></li>
        <li><a href="#vimapi">Vim Mode API</a>
            <ul>
                <li><a href="#vimapi_configuration">Configuration</a></li>
                <li><a href="#vimapi_extending">Extending VIM</a></li>
            </ul>
        </li>
    </ul>
</div>

<article>

    <section class=first id=overview>
        <h2 style="position: relative">
            User manual and reference guide
            <span style="color: #888; font-size: 1rem; position: absolute; right: 0; bottom: 0">version 5.52.0</span>
        </h2>

        <p>CodeMirror is a code-editor component that can be embedded in
            Web pages. The core library provides <em>only</em> the editor
            component, no accompanying buttons, auto-completion, or other IDE
            functionality. It does provide a rich API on top of which such
            functionality can be straightforwardly implemented. See
            the <a href="#addons">addons</a> included in the distribution,
            and the <a href="https://github.com/codemirror/CodeMirror/wiki/CodeMirror-addons">list
                of externally hosted addons</a>, for reusable
            implementations of extra features.</p>

        <p>CodeMirror works with language-specific modes. Modes are
            JavaScript programs that help color (and optionally indent) text
            written in a given language. The distribution comes with a number
            of modes (see the <a href="../mode/"><code>mode/</code></a>
            directory), and it isn't hard to <a href="#modeapi">write new
                ones</a> for other languages.</p>
    </section>

    <section id=usage>
        <h2>Basic Usage</h2>

        <p>The easiest way to use CodeMirror is to simply load the script
            and style sheet found under <code>lib/</code> in the distribution,
            plus a mode script from one of the <code>mode/</code> directories.
            For example:</p>

        <pre data-lang="text/html">&lt;script src="lib/codemirror.js">&lt;/script>
&lt;link rel="stylesheet" href="lib/codemirror.css">
&lt;script src="mode/javascript/javascript.js">&lt;/script></pre>

        <p>(Alternatively, use a module loader. <a href="#modloader">More
            about that later.</a>)</p>

        <p>Having done this, an editor instance can be created like
            this:</p>

        <pre data-lang="javascript">var myCodeMirror = CodeMirror(document.body);</pre>

        <p>The editor will be appended to the document body, will start
            empty, and will use the mode that we loaded. To have more control
            over the new editor, a configuration object can be passed
            to <a href="#CodeMirror"><code>CodeMirror</code></a> as a second
            argument:</p>

        <pre data-lang="javascript">var myCodeMirror = CodeMirror(document.body, {
  value: "function myScript(){return 100;}\n",
  mode:  "javascript"
});</pre>

        <p>This will initialize the editor with a piece of code already in
            it, and explicitly tell it to use the JavaScript mode (which is
            useful when multiple modes are loaded).
            See <a href="#config">below</a> for a full discussion of the
            configuration options that CodeMirror accepts.</p>

        <p>In cases where you don't want to append the editor to an
            element, and need more control over the way it is inserted, the
            first argument to the <code>CodeMirror</code> function can also
            be a function that, when given a DOM element, inserts it into the
            document somewhere. This could be used to, for example, replace a
            textarea with a real editor:</p>

        <pre data-lang="javascript">var myCodeMirror = CodeMirror(function(elt) {
  myTextArea.parentNode.replaceChild(elt, myTextArea);
}, {value: myTextArea.value});</pre>

        <p>However, for this use case, which is a common way to use
            CodeMirror, the library provides a much more powerful
            shortcut:</p>

        <pre data-lang="javascript">var myCodeMirror = CodeMirror.fromTextArea(myTextArea);</pre>

        <p>This will, among other things, ensure that the textarea's value
            is updated with the editor's contents when the form (if it is part
            of a form) is submitted. See the <a href="#fromTextArea">API
                reference</a> for a full description of this method.</p>

        <h3 id=modloader>Module loaders</h3>

        <p>The files in the CodeMirror distribution contain shims for
            loading them (and their dependencies) in AMD or CommonJS
            environments. If the variables <code>exports</code>
            and <code>module</code> exist and have type object, CommonJS-style
            require will be used. If not, but there is a
            function <code>define</code> with an <code>amd</code> property
            present, AMD-style (RequireJS) will be used.</p>

        <p>It is possible to
            use <a href="http://browserify.org/">Browserify</a> or similar
            tools to statically build modules using CodeMirror. Alternatively,
            use <a href="http://requirejs.org/">RequireJS</a> to dynamically
            load dependencies at runtime. Both of these approaches have the
            advantage that they don't use the global namespace and can, thus,
            do things like load multiple versions of CodeMirror alongside each
            other.</p>

        <p>Here's a simple example of using RequireJS to load CodeMirror:</p>

        <pre data-lang="javascript">require([
  "cm/lib/codemirror", "cm/mode/htmlmixed/htmlmixed"
], function(CodeMirror) {
  CodeMirror.fromTextArea(document.getElementById("code"), {
    lineNumbers: true,
    mode: "htmlmixed"
  });
});</pre>

        <p>It will automatically load the modes that the mixed HTML mode
            depends on (XML, JavaScript, and CSS). Do <em>not</em> use
            RequireJS' <code>paths</code> option to configure the path to
            CodeMirror, since it will break loading submodules through
            relative paths. Use
            the <a href="http://requirejs.org/docs/api.html#packages"><code>packages</code></a>
            configuration option instead, as in:</p>

        <pre data-lang=javascript>require.config({
  packages: [{
    name: "codemirror",
    location: "../path/to/codemirror",
    main: "lib/codemirror"
  }]
});</pre>

    </section>

    <section id=config>
        <h2>Configuration</h2>

        <p>Both the <a href="#CodeMirror"><code>CodeMirror</code></a>
            function and its <code>fromTextArea</code> method take as second
            (optional) argument an object containing configuration options.
            Any option not supplied like this will be taken
            from <a href="#defaults"><code>CodeMirror.defaults</code></a>, an
            object containing the default options. You can update this object
            to change the defaults on your page.</p>

        <p>Options are not checked in any way, so setting bogus option
            values is bound to lead to odd errors.</p>

        <p>These are the supported options:</p>

        <dl>
            <dt id="option_value"><code><strong>value</strong>: string|CodeMirror.Doc</code></dt>
            <dd>The starting value of the editor. Can be a string, or
                a <a href="#api_doc">document object</a>.
            </dd>

            <dt id="option_mode"><code><strong>mode</strong>: string|object</code></dt>
            <dd>The mode to use. When not given, this will default to the
                first mode that was loaded. It may be a string, which either
                simply names the mode or is
                a <a href="http://en.wikipedia.org/wiki/MIME">MIME</a> type
                associated with the mode. The value <code>"null"</code>
                indicates no highlighting should be applied. Alternatively, it
                may be an object containing configuration options for the mode,
                with a <code>name</code> property that names the mode (for
                example <code>{name: "javascript", json: true}</code>). The demo
                pages for each mode contain information about what configuration
                parameters the mode supports. You can ask CodeMirror which modes
                and MIME types have been defined by inspecting
                the <code>CodeMirror.modes</code>
                and <code>CodeMirror.mimeModes</code> objects. The first maps
                mode names to their constructors, and the second maps MIME types
                to mode specs.
            </dd>

            <dt id="option_lineSeparator"><code><strong>lineSeparator</strong>: string|null</code></dt>
            <dd>Explicitly set the line separator for the editor. By default
                (value <code>null</code>), the document will be split on CRLFs
                as well as lone CRs and LFs, and a single LF will be used as
                line separator in all output (such
                as <a href="#getValue"><code>getValue</code></a>). When a
                specific string is given, lines will only be split on that
                string, and output will, by default, use that same
                separator.
            </dd>

            <dt id="option_theme"><code><strong>theme</strong>: string</code></dt>
            <dd>The theme to style the editor with. You must make sure the
                CSS file defining the corresponding <code>.cm-s-[name]</code>
                styles is loaded (see
                the <a href="../theme/"><code>theme</code></a> directory in the
                distribution). The default is <code>"default"</code>, for which
                colors are included in <code>codemirror.css</code>. It is
                possible to use multiple theming classes at once—for
                example <code>"foo bar"</code> will assign both
                the <code>cm-s-foo</code> and the <code>cm-s-bar</code> classes
                to the editor.
            </dd>

            <dt id="option_indentUnit"><code><strong>indentUnit</strong>: integer</code></dt>
            <dd>How many spaces a block (whatever that means in the edited
                language) should be indented. The default is 2.
            </dd>

            <dt id="option_smartIndent"><code><strong>smartIndent</strong>: boolean</code></dt>
            <dd>Whether to use the context-sensitive indentation that the
                mode provides (or just indent the same as the line before).
                Defaults to true.
            </dd>

            <dt id="option_tabSize"><code><strong>tabSize</strong>: integer</code></dt>
            <dd>The width of a tab character. Defaults to 4.</dd>

            <dt id="option_indentWithTabs"><code><strong>indentWithTabs</strong>: boolean</code></dt>
            <dd>Whether, when indenting, the first N*<code>tabSize</code>
                spaces should be replaced by N tabs. Default is false.
            </dd>

            <dt id="option_electricChars"><code><strong>electricChars</strong>: boolean</code></dt>
            <dd>Configures whether the editor should re-indent the current
                line when a character is typed that might change its proper
                indentation (only works if the mode supports indentation).
                Default is true.
            </dd>

            <dt id="option_specialChars"><code><strong>specialChars</strong>: RegExp</code></dt>
            <dd>A regular expression used to determine which characters
                should be replaced by a
                special <a href="#option_specialCharPlaceholder">placeholder</a>.
                Mostly useful for non-printing special characters. The default
                is <code>/[\u0000-\u001f\u007f-\u009f\u00ad\u061c\u200b-\u200f\u2028\u2029\ufeff\ufff9-\ufffc]/</code>.
            </dd>
            <dt id="option_specialCharPlaceholder"><code><strong>specialCharPlaceholder</strong>:
                function(char) → Element</code></dt>
            <dd>A function that, given a special character identified by
                the <a href="#option_specialChars"><code>specialChars</code></a>
                option, produces a DOM node that is used to represent the
                character. By default, a red dot (<span style="color: red">•</span>)
                is shown, with a title tooltip to indicate the character code.
            </dd>

            <dt id="option_direction"><code><strong>direction</strong>: "ltr" | "rtl"</code></dt>
            <dd>Flips overall layout and selects base paragraph direction to
                be left-to-right or right-to-left. Default is "ltr".
                CodeMirror applies the Unicode Bidirectional Algorithm to each
                line, but does not autodetect base direction — it's set to the
                editor direction for all lines. The resulting order is
                sometimes wrong when base direction doesn't match user intent
                (for example, leading and trailing punctuation jumps to the
                wrong side of the line). Therefore, it's helpful for
                multilingual input to let users toggle this option.

            <dt id="option_rtlMoveVisually"><code><strong>rtlMoveVisually</strong>: boolean</code></dt>
            <dd>Determines whether horizontal cursor movement through
                right-to-left (Arabic, Hebrew) text is visual (pressing the left
                arrow moves the cursor left) or logical (pressing the left arrow
                moves to the next lower index in the string, which is visually
                right in right-to-left text). The default is <code>false</code>
                on Windows, and <code>true</code> on other platforms.
            </dd>

            <dt id="option_keyMap"><code><strong>keyMap</strong>: string</code></dt>
            <dd>Configures the key map to use. The default
                is <code>"default"</code>, which is the only key map defined
                in <code>codemirror.js</code> itself. Extra key maps are found in
                the <a href="../keymap/"><code>key map</code></a> directory. See
                the <a href="#keymaps">section on key maps</a> for more
                information.
            </dd>

            <dt id="option_extraKeys"><code><strong>extraKeys</strong>: object</code></dt>
            <dd>Can be used to specify extra key bindings for the editor,
                alongside the ones defined
                by <a href="#option_keyMap"><code>keyMap</code></a>. Should be
                either null, or a valid <a href="#keymaps">key map</a> value.
            </dd>

            <dt id="option_configureMouse"><code><strong>configureMouse</strong>: fn(cm: CodeMirror, repeat: "single" |
                "double" | "triple", event: Event) → Object</code></dt>
            <dd>Allows you to configure the behavior of mouse selection and
                dragging. The function is called when the left mouse button is
                pressed. The returned object may have the following properties:
                <dl>
                    <dt><code><strong>unit</strong>: "char" | "word" | "line" | "rectangle" | fn(CodeMirror, Pos) →
                        {from: Pos, to: Pos}</code></dt>
                    <dd>The unit by which to select. May be one of the built-in
                        units or a function that takes a position and returns a
                        range around that, for a custom unit. The default is to
                        return <code>"word"</code> for double
                        clicks, <code>"line"</code> for triple
                        clicks, <code>"rectangle"</code> for alt-clicks (or, on
                        Chrome OS, meta-shift-clicks), and <code>"single"</code>
                        otherwise.
                    </dd>
                    <dt><code><strong>extend</strong>: bool</code></dt>
                    <dd>Whether to extend the existing selection range or start
                        a new one. By default, this is enabled when shift
                        clicking.
                    </dd>
                    <dt><code><strong>addNew</strong>: bool</code></dt>
                    <dd>When enabled, this adds a new range to the existing
                        selection, rather than replacing it. The default behavior is
                        to enable this for command-click on Mac OS, and
                        control-click on other platforms.
                    </dd>
                    <dt><code><strong>moveOnDrag</strong>: bool</code></dt>
                    <dd>When the mouse even drags content around inside the
                        editor, this controls whether it is copied (false) or moved
                        (true). By default, this is enabled by alt-clicking on Mac
                        OS, and ctrl-clicking elsewhere.
                    </dd>
                </dl>
            </dd>

            <dt id="option_lineWrapping"><code><strong>lineWrapping</strong>: boolean</code></dt>
            <dd>Whether CodeMirror should scroll or wrap for long lines.
                Defaults to <code>false</code> (scroll).
            </dd>

            <dt id="option_lineNumbers"><code><strong>lineNumbers</strong>: boolean</code></dt>
            <dd>Whether to show line numbers to the left of the editor.</dd>

            <dt id="option_firstLineNumber"><code><strong>firstLineNumber</strong>: integer</code></dt>
            <dd>At which number to start counting lines. Default is 1.</dd>

            <dt id="option_lineNumberFormatter"><code><strong>lineNumberFormatter</strong>: function(line: integer) →
                string</code></dt>
            <dd>A function used to format line numbers. The function is
                passed the line number, and should return a string that will be
                shown in the gutter.
            </dd>

            <dt id="option_gutters"><code><strong>gutters</strong>: array&lt;string | {className: string, style:
                ?string}&gt;</code></dt>
            <dd>Can be used to add extra gutters (beyond or instead of the
                line number gutter). Should be an array of CSS class names or
                class name / CSS string pairs, each of which defines
                a <code>width</code> (and optionally a background), and which
                will be used to draw the background of the gutters. <em>May</em>
                include the <code>CodeMirror-linenumbers</code> class, in order
                to explicitly set the position of the line number gutter (it
                will default to be to the right of all other gutters). These
                class names are the keys passed
                to <a href="#setGutterMarker"><code>setGutterMarker</code></a>.
            </dd>

            <dt id="option_fixedGutter"><code><strong>fixedGutter</strong>: boolean</code></dt>
            <dd>Determines whether the gutter scrolls along with the content
                horizontally (false) or whether it stays fixed during horizontal
                scrolling (true, the default).
            </dd>

            <dt id="option_scrollbarStyle"><code><strong>scrollbarStyle</strong>: string</code></dt>
            <dd>Chooses a scrollbar implementation. The default
                is <code>"native"</code>, showing native scrollbars. The core
                library also provides the <code>"null"</code> style, which
                completely hides the
                scrollbars. <a href="#addon_simplescrollbars">Addons</a> can
                implement additional scrollbar models.
            </dd>

            <dt id="option_coverGutterNextToScrollbar"><code><strong>coverGutterNextToScrollbar</strong>: boolean</code>
            </dt>
            <dd>When <a href="#option_fixedGutter"><code>fixedGutter</code></a>
                is on, and there is a horizontal scrollbar, by default the
                gutter will be visible to the left of this scrollbar. If this
                option is set to true, it will be covered by an element with
                class <code>CodeMirror-gutter-filler</code>.
            </dd>

            <dt id="option_inputStyle"><code><strong>inputStyle</strong>: string</code></dt>
            <dd>Selects the way CodeMirror handles input and focus. The core
                library defines the <code>"textarea"</code>
                and <code>"contenteditable"</code> input models. On mobile
                browsers, the default is <code>"contenteditable"</code>. On
                desktop browsers, the default is <code>"textarea"</code>.
                Support for IME and screen readers is better in
                the <code>"contenteditable"</code> model. The intention is to
                make it the default on modern desktop browsers in the
                future.
            </dd>

            <dt id="option_readOnly"><code><strong>readOnly</strong>: boolean|string</code></dt>
            <dd>This disables editing of the editor content by the user. If
                the special value <code>"nocursor"</code> is given (instead of
                simply <code>true</code>), focusing of the editor is also
                disallowed.
            </dd>

            <dt id="option_showCursorWhenSelecting"><code><strong>showCursorWhenSelecting</strong>: boolean</code></dt>
            <dd>Whether the cursor should be drawn when a selection is
                active. Defaults to false.
            </dd>

            <dt id="option_lineWiseCopyCut"><code><strong>lineWiseCopyCut</strong>: boolean</code></dt>
            <dd>When enabled, which is the default, doing copy or cut when
                there is no selection will copy or cut the whole lines that have
                cursors on them.
            </dd>

            <dt id="option_pasteLinesPerSelection"><code><strong>pasteLinesPerSelection</strong>: boolean</code></dt>
            <dd>When pasting something from an external source (not from the
                editor itself), if the number of lines matches the number of
                selection, CodeMirror will by default insert one line per
                selection. You can set this to <code>false</code> to disable
                that behavior.
            </dd>

            <dt id="option_selectionsMayTouch"><code><strong>selectionsMayTouch</strong>: boolean</code></dt>
            <dd>Determines whether multiple selections are joined as soon as
                they touch (the default) or only when they overlap (true).
            </dd>

            <dt id="option_undoDepth"><code><strong>undoDepth</strong>: integer</code></dt>
            <dd>The maximum number of undo levels that the editor stores.
                Note that this includes selection change events. Defaults to
                200.
            </dd>

            <dt id="option_historyEventDelay"><code><strong>historyEventDelay</strong>: integer</code></dt>
            <dd>The period of inactivity (in milliseconds) that will cause a
                new history event to be started when typing or deleting.
                Defaults to 1250.
            </dd>

            <dt id="option_tabindex"><code><strong>tabindex</strong>: integer</code></dt>
            <dd>The <a href="http://www.w3.org/TR/html401/interact/forms.html#adef-tabindex">tab
                index</a> to assign to the editor. If not given, no tab index
                will be assigned.
            </dd>

            <dt id="option_autofocus"><code><strong>autofocus</strong>: boolean</code></dt>
            <dd>Can be used to make CodeMirror focus itself on
                initialization. Defaults to off.
                When <a href="#fromTextArea"><code>fromTextArea</code></a> is
                used, and no explicit value is given for this option, it will be
                set to true when either the source textarea is focused, or it
                has an <code>autofocus</code> attribute and no other element is
                focused.
            </dd>

            <dt id="option_phrases"><code><strong>phrases</strong>: ?object</code></dt>
            <dd>Some addons run user-visible strings (such as labels in the
                interface) through the <a href="#phrase"><code>phrase</code></a>
                method to allow for translation. This option determines the
                return value of that method. When it is null or an object that
                doesn't have a property named by the input string, that string
                is returned. Otherwise, the value of the property corresponding
                to that string is returned.
            </dd>
        </dl>

        <p>Below this a few more specialized, low-level options are
            listed. These are only useful in very specific situations, you
            might want to skip them the first time you read this manual.</p>

        <dl>
            <dt id="option_dragDrop"><code><strong>dragDrop</strong>: boolean</code></dt>
            <dd>Controls whether drag-and-drop is enabled. On by default.</dd>

            <dt id="option_allowDropFileTypes"><code><strong>allowDropFileTypes</strong>: array&lt;string&gt;</code>
            </dt>
            <dd>When set (default is <code>null</code>) only files whose
                type is in the array can be dropped into the editor. The strings
                should be MIME types, and will be checked against
                the <a href="https://w3c.github.io/FileAPI/#dfn-type"><code>type</code></a>
                of the <code>File</code> object as reported by the browser.
            </dd>

            <dt id="option_cursorBlinkRate"><code><strong>cursorBlinkRate</strong>: number</code></dt>
            <dd>Half-period in milliseconds used for cursor blinking. The default blink
                rate is 530ms. By setting this to zero, blinking can be disabled. A
                negative value hides the cursor entirely.
            </dd>

            <dt id="option_cursorScrollMargin"><code><strong>cursorScrollMargin</strong>: number</code></dt>
            <dd>How much extra space to always keep above and below the
                cursor when approaching the top or bottom of the visible view in
                a scrollable document. Default is 0.
            </dd>

            <dt id="option_cursorHeight"><code><strong>cursorHeight</strong>: number</code></dt>
            <dd>Determines the height of the cursor. Default is 1, meaning
                it spans the whole height of the line. For some fonts (and by
                some tastes) a smaller height (for example <code>0.85</code>),
                which causes the cursor to not reach all the way to the bottom
                of the line, looks better
            </dd>

            <dt id="option_resetSelectionOnContextMenu"><code><strong>resetSelectionOnContextMenu</strong>:
                boolean</code></dt>
            <dd>Controls whether, when the context menu is opened with a
                click outside of the current selection, the cursor is moved to
                the point of the click. Defaults to <code>true</code>.
            </dd>

            <dt id="option_workTime"><code id="option_wordkDelay"><strong>workTime</strong>, <strong>workDelay</strong>:
                number</code></dt>
            <dd>Highlighting is done by a pseudo background-thread that will
                work for <code>workTime</code> milliseconds, and then use
                timeout to sleep for <code>workDelay</code> milliseconds. The
                defaults are 200 and 300, you can change these options to make
                the highlighting more or less aggressive.
            </dd>

            <dt id="option_pollInterval"><code><strong>pollInterval</strong>: number</code></dt>
            <dd>Indicates how quickly CodeMirror should poll its input
                textarea for changes (when focused). Most input is captured by
                events, but some things, like IME input on some browsers, don't
                generate events that allow CodeMirror to properly detect it.
                Thus, it polls. Default is 100 milliseconds.
            </dd>

            <dt id="option_flattenSpans"><code><strong>flattenSpans</strong>: boolean</code></dt>
            <dd>By default, CodeMirror will combine adjacent tokens into a
                single span if they have the same class. This will result in a
                simpler DOM tree, and thus perform better. With some kinds of
                styling (such as rounded corners), this will change the way the
                document looks. You can set this option to false to disable this
                behavior.
            </dd>

            <dt id="option_addModeClass"><code><strong>addModeClass</strong>: boolean</code></dt>
            <dd>When enabled (off by default), an extra CSS class will be
                added to each token, indicating the
                (<a href="#innerMode">inner</a>) mode that produced it, prefixed
                with <code>"cm-m-"</code>. For example, tokens from the XML mode
                will get the <code>cm-m-xml</code> class.
            </dd>

            <dt id="option_maxHighlightLength"><code><strong>maxHighlightLength</strong>: number</code></dt>
            <dd>When highlighting long lines, in order to stay responsive,
                the editor will give up and simply style the rest of the line as
                plain text when it reaches a certain position. The default is
                10 000. You can set this to <code>Infinity</code> to turn off
                this behavior.
            </dd>

            <dt id="option_viewportMargin"><code><strong>viewportMargin</strong>: integer</code></dt>
            <dd>Specifies the amount of lines that are rendered above and
                below the part of the document that's currently scrolled into
                view. This affects the amount of updates needed when scrolling,
                and the amount of work that such an update does. You should
                usually leave it at its default, 10. Can be set
                to <code>Infinity</code> to make sure the whole document is
                always rendered, and thus the browser's text search works on it.
                This <em>will</em> have bad effects on performance of big
                documents.
            </dd>

            <dt id="option_spellcheck"><code><strong>spellcheck</strong>: boolean</code></dt>
            <dd>Specifies whether or not spellcheck will be enabled on the input.</dd>

            <dt id="option_autocorrect"><code><strong>autocorrect</strong>: boolean</code></dt>
            <dd>Specifies whether or not autocorrect will be enabled on the input.</dd>

            <dt id="option_autocapitalize"><code><strong>autocapitalize</strong>: boolean</code></dt>
            <dd>Specifies whether or not autocapitalization will be enabled on the input.</dd>
        </dl>
    </section>

    <section id=events>
        <h2>Events</h2>

        <p>Various CodeMirror-related objects emit events, which allow
            client code to react to various situations. Handlers for such
            events can be registered with the <a href="#on"><code>on</code></a>
            and <a href="#off"><code>off</code></a> methods on the objects
            that the event fires on. To fire your own events,
            use <code>CodeMirror.signal(target, name, args...)</code>,
            where <code>target</code> is a non-DOM-node object.</p>

        <p>An editor instance fires the following events.
            The <code>instance</code> argument always refers to the editor
            itself.</p>

        <dl>
            <dt id="event_change"><code><strong>"change"</strong> (instance: CodeMirror, changeObj: object)</code></dt>
            <dd>Fires every time the content of the editor is changed.
                The <code>changeObj</code> is a <code>{from, to, text, removed,
                    origin}</code> object containing information about the changes
                that occurred as second argument. <code>from</code>
                and <code>to</code> are the positions (in the pre-change
                coordinate system) where the change started and ended (for
                example, it might be <code>{ch:0, line:18}</code> if the
                position is at the beginning of line #19). <code>text</code> is
                an array of strings representing the text that replaced the
                changed range (split by line). <code>removed</code> is the text
                that used to be between <code>from</code> and <code>to</code>,
                which is overwritten by this change. This event is
                fired <em>before</em> the end of
                an <a href="#operation">operation</a>, before the DOM updates
                happen.
            </dd>

            <dt id="event_changes"><code><strong>"changes"</strong> (instance: CodeMirror, changes: array&lt;object&gt;)</code>
            </dt>
            <dd>Like the <a href="#event_change"><code>"change"</code></a>
                event, but batched per <a href="#operation">operation</a>,
                passing an array containing all the changes that happened in the
                operation. This event is fired after the operation finished, and
                display changes it makes will trigger a new operation.
            </dd>

            <dt id="event_beforeChange"><code><strong>"beforeChange"</strong> (instance: CodeMirror, changeObj: object)</code>
            </dt>
            <dd>This event is fired before a change is applied, and its
                handler may choose to modify or cancel the change.
                The <code>changeObj</code> object
                has <code>from</code>, <code>to</code>, and <code>text</code>
                properties, as with
                the <a href="#event_change"><code>"change"</code></a> event. It
                also has a <code>cancel()</code> method, which can be called to
                cancel the change, and, <strong>if</strong> the change isn't
                coming from an undo or redo event, an <code>update(from, to,
                    text)</code> method, which may be used to modify the change.
                Undo or redo changes can't be modified, because they hold some
                metainformation for restoring old marked ranges that is only
                valid for that specific change. All three arguments
                to <code>update</code> are optional, and can be left off to
                leave the existing value for that field
                intact. <strong>Note:</strong> you may not do anything from
                a <code>"beforeChange"</code> handler that would cause changes
                to the document or its visualization. Doing so will, since this
                handler is called directly from the bowels of the CodeMirror
                implementation, probably cause the editor to become
                corrupted.
            </dd>

            <dt id="event_cursorActivity"><code><strong>"cursorActivity"</strong> (instance: CodeMirror)</code></dt>
            <dd>Will be fired when the cursor or selection moves, or any
                change is made to the editor content.
            </dd>

            <dt id="event_keyHandled"><code><strong>"keyHandled"</strong> (instance: CodeMirror, name: string, event:
                Event)</code></dt>
            <dd>Fired after a key is handled through a
                key map. <code>name</code> is the name of the handled key (for
                example <code>"Ctrl-X"</code> or <code>"'q'"</code>),
                and <code>event</code> is the DOM <code>keydown</code>
                or <code>keypress</code> event.
            </dd>

            <dt id="event_inputRead"><code><strong>"inputRead"</strong> (instance: CodeMirror, changeObj: object)</code>
            </dt>
            <dd>Fired whenever new input is read from the hidden textarea
                (typed or pasted by the user).
            </dd>

            <dt id="event_electricInput"><code><strong>"electricInput"</strong> (instance: CodeMirror, line:
                integer)</code></dt>
            <dd>Fired if text input matched the
                mode's <a href="#option_electricChars">electric</a> patterns,
                and this caused the line's indentation to change.
            </dd>

            <dt id="event_beforeSelectionChange"><code><strong>"beforeSelectionChange"</strong> (instance: CodeMirror,
                obj: {ranges, origin, update})</code></dt>
            <dd>This event is fired before the selection is moved. Its
                handler may inspect the set of selection ranges, present as an
                array of <code>{anchor, head}</code> objects in
                the <code>ranges</code> property of the <code>obj</code>
                argument, and optionally change them by calling
                the <code>update</code> method on this object, passing an array
                of ranges in the same format. The object also contains
                an <code>origin</code> property holding the origin string passed
                to the selection-changing method, if any. Handlers for this
                event have the same restriction
                as <a href="#event_beforeChange"><code>"beforeChange"</code></a>
                handlers — they should not do anything to directly update the
                state of the editor.
            </dd>

            <dt id="event_viewportChange"><code><strong>"viewportChange"</strong> (instance: CodeMirror, from: number,
                to: number)</code></dt>
            <dd>Fires whenever the <a href="#getViewport">view port</a> of
                the editor changes (due to scrolling, editing, or any other
                factor). The <code>from</code> and <code>to</code> arguments
                give the new start and end of the viewport.
            </dd>

            <dt id="event_swapDoc"><code><strong>"swapDoc"</strong> (instance: CodeMirror, oldDoc: Doc)</code></dt>
            <dd>This is signalled when the editor's document is replaced
                using the <a href="#swapDoc"><code>swapDoc</code></a>
                method.
            </dd>

            <dt id="event_gutterClick"><code><strong>"gutterClick"</strong> (instance: CodeMirror, line: integer,
                gutter: string, clickEvent: Event)</code></dt>
            <dd>Fires when the editor gutter (the line-number area) is
                clicked. Will pass the editor instance as first argument, the
                (zero-based) number of the line that was clicked as second
                argument, the CSS class of the gutter that was clicked as third
                argument, and the raw <code>mousedown</code> event object as
                fourth argument.
            </dd>

            <dt id="event_gutterContextMenu"><code><strong>"gutterContextMenu"</strong> (instance: CodeMirror, line:
                integer, gutter: string, contextMenu: Event: Event)</code></dt>
            <dd>Fires when the editor gutter (the line-number area)
                receives a <code>contextmenu</code> event. Will pass the editor
                instance as first argument, the (zero-based) number of the line
                that was clicked as second argument, the CSS class of the
                gutter that was clicked as third argument, and the raw
                <code>contextmenu</code> mouse event object as fourth argument.
                You can <code>preventDefault</code> the event, to signal that
                CodeMirror should do no further handling.
            </dd>

            <dt id="event_focus"><code><strong>"focus"</strong> (instance: CodeMirror, event: Event)</code></dt>
            <dd>Fires whenever the editor is focused.</dd>

            <dt id="event_blur"><code><strong>"blur"</strong> (instance: CodeMirror, event: Event)</code></dt>
            <dd>Fires whenever the editor is unfocused.</dd>

            <dt id="event_scroll"><code><strong>"scroll"</strong> (instance: CodeMirror)</code></dt>
            <dd>Fires when the editor is scrolled.</dd>

            <dt id="event_refresh"><code><strong>"refresh"</strong> (instance: CodeMirror)</code></dt>
            <dd>Fires when the editor is <a href="#refresh">refreshed</a>
                or <a href="#setSize">resized</a>. Mostly useful to invalidate
                cached values that depend on the editor or character size.
            </dd>

            <dt id="event_optionChange"><code><strong>"optionChange"</strong> (instance: CodeMirror, option:
                string)</code></dt>
            <dd>Dispatched every time an option is changed with <a href="#setOption"><code>setOption</code></a>.</dd>

            <dt id="event_scrollCursorIntoView"><code><strong>"scrollCursorIntoView"</strong> (instance: CodeMirror,
                event: Event)</code></dt>
            <dd>Fires when the editor tries to scroll its cursor into view.
                Can be hooked into to take care of additional scrollable
                containers around the editor. When the event object has
                its <code>preventDefault</code> method called, CodeMirror will
                not itself try to scroll the window.
            </dd>

            <dt id="event_update"><code><strong>"update"</strong> (instance: CodeMirror)</code></dt>
            <dd>Will be fired whenever CodeMirror updates its DOM display.</dd>

            <dt id="event_renderLine"><code><strong>"renderLine"</strong> (instance: CodeMirror, line: LineHandle,
                element: Element)</code></dt>
            <dd>Fired whenever a line is (re-)rendered to the DOM. Fired
                right after the DOM element is built, <em>before</em> it is
                added to the document. The handler may mess with the style of
                the resulting element, or add event handlers, but
                should <em>not</em> try to change the state of the editor.
            </dd>

            <dt id="event_dom"><code><strong>"mousedown"</strong>,
                <strong>"dblclick"</strong>, <strong>"touchstart"</strong>, <strong>"contextmenu"</strong>,
                <strong>"keydown"</strong>, <strong>"keypress"</strong>,
                <strong>"keyup"</strong>, <strong>"cut"</strong>, <strong>"copy"</strong>, <strong>"paste"</strong>,
                <strong>"dragstart"</strong>, <strong>"dragenter"</strong>,
                <strong>"dragover"</strong>, <strong>"dragleave"</strong>,
                <strong>"drop"</strong>
                (instance: CodeMirror, event: Event)</code></dt>
            <dd>Fired when CodeMirror is handling a DOM event of this type.
                You can <code>preventDefault</code> the event, or give it a
                truthy <code>codemirrorIgnore</code> property, to signal that
                CodeMirror should do no further handling.
            </dd>
        </dl>

        <p>Document objects (instances
            of <a href="#Doc"><code>CodeMirror.Doc</code></a>) emit the
            following events:</p>

        <dl>
            <dt id="event_doc_change"><code><strong>"change"</strong> (doc: CodeMirror.Doc, changeObj: object)</code>
            </dt>
            <dd>Fired whenever a change occurs to the
                document. <code>changeObj</code> has a similar type as the
                object passed to the
                editor's <a href="#event_change"><code>"change"</code></a>
                event.
            </dd>

            <dt id="event_doc_beforeChange"><code><strong>"beforeChange"</strong> (doc: CodeMirror.Doc, change: object)</code>
            </dt>
            <dd>See the <a href="#event_beforeChange">description of the
                same event</a> on editor instances.
            </dd>

            <dt id="event_doc_cursorActivity"><code><strong>"cursorActivity"</strong> (doc: CodeMirror.Doc)</code></dt>
            <dd>Fired whenever the cursor or selection in this document
                changes.
            </dd>

            <dt id="event_doc_beforeSelectionChange"><code><strong>"beforeSelectionChange"</strong> (doc:
                CodeMirror.Doc, selection: {head, anchor})</code></dt>
            <dd>Equivalent to
                the <a href="#event_beforeSelectionChange">event by the same
                    name</a> as fired on editor instances.
            </dd>
        </dl>

        <p>Line handles (as returned by, for
            example, <a href="#getLineHandle"><code>getLineHandle</code></a>)
            support these events:</p>

        <dl>
            <dt id="event_delete"><code><strong>"delete"</strong> ()</code></dt>
            <dd>Will be fired when the line object is deleted. A line object
                is associated with the <em>start</em> of the line. Mostly useful
                when you need to find out when your <a href="#setGutterMarker">gutter
                    markers</a> on a given line are removed.
            </dd>
            <dt id="event_line_change"><code><strong>"change"</strong> (line: LineHandle, changeObj: object)</code></dt>
            <dd>Fires when the line's text content is changed in any way
                (but the line is not deleted outright). The <code>change</code>
                object is similar to the one passed
                to <a href="#event_change">change event</a> on the editor
                object.
            </dd>
        </dl>

        <p>Marked range handles (<code>CodeMirror.TextMarker</code>), as returned
            by <a href="#markText"><code>markText</code></a>
            and <a href="#setBookmark"><code>setBookmark</code></a>, emit the
            following events:</p>

        <dl>
            <dt id="event_beforeCursorEnter"><code><strong>"beforeCursorEnter"</strong> ()</code></dt>
            <dd>Fired when the cursor enters the marked range. From this
                event handler, the editor state may be inspected
                but <em>not</em> modified, with the exception that the range on
                which the event fires may be cleared.
            </dd>
            <dt id="event_clear"><code><strong>"clear"</strong> (from: {line, ch}, to: {line, ch})</code></dt>
            <dd>Fired when the range is cleared, either through cursor
                movement in combination
                with <a href="#mark_clearOnEnter"><code>clearOnEnter</code></a>
                or through a call to its <code>clear()</code> method. Will only
                be fired once per handle. Note that deleting the range through
                text editing does not fire this event, because an undo action
                might bring the range back into existence. <code>from</code>
                and <code>to</code> give the part of the document that the range
                spanned when it was cleared.
            </dd>
            <dt id="event_hide"><code><strong>"hide"</strong> ()</code></dt>
            <dd>Fired when the last part of the marker is removed from the
                document by editing operations.
            </dd>
            <dt id="event_unhide"><code><strong>"unhide"</strong> ()</code></dt>
            <dd>Fired when, after the marker was removed by editing, a undo
                operation brought the marker back.
            </dd>
        </dl>

        <p>Line widgets (<code>CodeMirror.LineWidget</code>), returned
            by <a href="#addLineWidget"><code>addLineWidget</code></a>, fire
            these events:</p>

        <dl>
            <dt id="event_redraw"><code><strong>"redraw"</strong> ()</code></dt>
            <dd>Fired whenever the editor re-adds the widget to the DOM.
                This will happen once right after the widget is added (if it is
                scrolled into view), and then again whenever it is scrolled out
                of view and back in again, or when changes to the editor options
                or the line the widget is on require the widget to be
                redrawn.
            </dd>
        </dl>
    </section>

    <section id=keymaps>
        <h2>Key Maps</h2>

        <p>Key maps are ways to associate keys and mouse buttons with
            functionality. A key map is an object mapping strings that
            identify the buttons to functions that implement their
            functionality.</p>

        <p>The CodeMirror distributions comes
            with <a href="../demo/emacs.html">Emacs</a>, <a href="../demo/vim.html">Vim</a>,
            and <a href="../demo/sublime.html">Sublime Text</a>-style keymaps.</p>

        <p>Keys are identified either by name or by character.
            The <code>CodeMirror.keyNames</code> object defines names for
            common keys and associates them with their key codes. Examples of
            names defined here are <code>Enter</code>, <code>F5</code>,
            and <code>Q</code>. These can be prefixed
            with <code>Shift-</code>, <code>Cmd-</code>, <code>Ctrl-</code>,
            and <code>Alt-</code> to specify a modifier. So for
            example, <code>Shift-Ctrl-Space</code> would be a valid key
            identifier.</p>

        <p>Common example: map the Tab key to insert spaces instead of a tab
            character.</p>

        <pre data-lang="javascript">
editor.setOption("extraKeys", {
  Tab: function(cm) {
    var spaces = Array(cm.getOption("indentUnit") + 1).join(" ");
    cm.replaceSelection(spaces);
  }
});</pre>

        <p>Alternatively, a character can be specified directly by
            surrounding it in single quotes, for example <code>'$'</code>
            or <code>'q'</code>. Due to limitations in the way browsers fire
            key events, these may not be prefixed with modifiers.</p>

        <p>To bind mouse buttons, use the names `LeftClick`,
            `MiddleClick`, and `RightClick`. These can also be prefixed with
            modifiers, and in addition, the word `Double` or `Triple` can be
            put before `Click` (as in `LeftDoubleClick`) to bind a double- or
            triple-click. The function for such a binding is passed the
            position that was clicked as second argument.</p>

        <p id="normalizeKeyMap">Multi-stroke key bindings can be specified
            by separating the key names by spaces in the property name, for
            example <code>Ctrl-X Ctrl-V</code>. When a map contains
            multi-stoke bindings or keys with modifiers that are not specified
            in the default order (<code>Shift-Cmd-Ctrl-Alt</code>), you must
            call <code>CodeMirror.normalizeKeyMap</code> on it before it can
            be used. This function takes a keymap and modifies it to normalize
            modifier order and properly recognize multi-stroke bindings. It
            will return the keymap itself.</p>

        <p>The <code>CodeMirror.keyMap</code> object associates key maps
            with names. User code and key map definitions can assign extra
            properties to this object. Anywhere where a key map is expected, a
            string can be given, which will be looked up in this object. It
            also contains the <code>"default"</code> key map holding the
            default bindings.</p>

        <p>The values of properties in key maps can be either functions of
            a single argument (the CodeMirror instance), strings, or
            <code>false</code>. Strings refer
            to <a href="#commands">commands</a>, which are described below. If
            the property is set to <code>false</code>, CodeMirror leaves
            handling of the key up to the browser. A key handler function may
            return <code>CodeMirror.Pass</code> to indicate that it has
            decided not to handle the key, and other handlers (or the default
            behavior) should be given a turn.</p>

        <p>Keys mapped to command names that start with the
            characters <code>"go"</code> or to functions that have a
            truthy <code>motion</code> property (which should be used for
            cursor-movement actions) will be fired even when an
            extra <code>Shift</code> modifier is present (i.e. <code>"Up":
                "goLineUp"</code> matches both up and shift-up). This is used to
            easily implement shift-selection.</p>

        <p>Key maps can defer to each other by defining
            a <code>fallthrough</code> property. This indicates that when a
            key is not found in the map itself, one or more other maps should
            be searched. It can hold either a single key map or an array of
            key maps.</p>

        <p>When a key map needs to set something up when it becomes
            active, or tear something down when deactivated, it can
            contain <code>attach</code> and/or <code>detach</code> properties,
            which should hold functions that take the editor instance and the
            next or previous keymap. Note that this only works for the
            <a href="#option_keyMap">top-level keymap</a>, not for fallthrough
            maps or maps added
            with <a href="#option_extraKeys"><code>extraKeys</code></a>
            or <a href="#addKeyMap"><code>addKeyMap</code></a>.</p>
    </section>

    <section id=commands>
        <h2>Commands</h2>

        <p>Commands are parameter-less actions that can be performed on an
            editor. Their main use is for key bindings. Commands are defined by
            adding properties to the <code>CodeMirror.commands</code> object.
            A number of common commands are defined by the library itself,
            most of them used by the default key bindings. The value of a
            command property must be a function of one argument (an editor
            instance).</p>

        <p>Some of the commands below are referenced in the default
            key map, but not defined by the core library. These are intended to
            be defined by user code or addons.</p>

        <p>Commands can also be run with
            the <a href="#execCommand"><code>execCommand</code></a>
            method.</p>

        <dl>
            <dt class=command id=command_selectAll><code><strong>selectAll</strong></code><span class=keybinding>Ctrl-A (PC), Cmd-A (Mac)</span>
            </dt>
            <dd>Select the whole content of the editor.</dd>

            <dt class=command id=command_singleSelection><code><strong>singleSelection</strong></code><span
                    class=keybinding>Esc</span></dt>
            <dd>When multiple selections are present, this deselects all but
                the primary selection.
            </dd>

            <dt class=command id=command_killLine><code><strong>killLine</strong></code><span class=keybinding>Ctrl-K (Mac)</span>
            </dt>
            <dd>Emacs-style line killing. Deletes the part of the line after
                the cursor. If that consists only of whitespace, the newline at
                the end of the line is also deleted.
            </dd>

            <dt class=command id=command_deleteLine><code><strong>deleteLine</strong></code><span class=keybinding>Ctrl-D (PC), Cmd-D (Mac)</span>
            </dt>
            <dd>Deletes the whole line under the cursor, including newline at the end.</dd>

            <dt class=command id=command_delLineLeft><code><strong>delLineLeft</strong></code></dt>
            <dd>Delete the part of the line before the cursor.</dd>

            <dt class=command id=command_delWrappedLineLeft><code><strong>delWrappedLineLeft</strong></code><span
                    class=keybinding>Cmd-Backspace (Mac)</span></dt>
            <dd>Delete the part of the line from the left side of the visual line the cursor is on to the cursor.</dd>

            <dt class=command id=command_delWrappedLineRight><code><strong>delWrappedLineRight</strong></code><span
                    class=keybinding>Cmd-Delete (Mac)</span></dt>
            <dd>Delete the part of the line from the cursor to the right side of the visual line the cursor is on.</dd>

            <dt class=command id=command_undo><code><strong>undo</strong></code><span class=keybinding>Ctrl-Z (PC), Cmd-Z (Mac)</span>
            </dt>
            <dd>Undo the last change. Note that, because browsers still
                don't make it possible for scripts to react to or customize the
                context menu, selecting undo (or redo) from the context menu in
                a CodeMirror instance does not work.
            </dd>

            <dt class=command id=command_redo><code><strong>redo</strong></code><span class=keybinding>Ctrl-Y (PC), Shift-Cmd-Z (Mac), Cmd-Y (Mac)</span>
            </dt>
            <dd>Redo the last undone change.</dd>

            <dt class=command id=command_undoSelection><code><strong>undoSelection</strong></code><span
                    class=keybinding>Ctrl-U (PC), Cmd-U (Mac)</span></dt>
            <dd>Undo the last change to the selection, or if there are no
                selection-only changes at the top of the history, undo the last
                change.
            </dd>

            <dt class=command id=command_redoSelection><code><strong>redoSelection</strong></code><span
                    class=keybinding>Alt-U (PC), Shift-Cmd-U (Mac)</span></dt>
            <dd>Redo the last change to the selection, or the last text change if
                no selection changes remain.
            </dd>

            <dt class=command id=command_goDocStart><code><strong>goDocStart</strong></code><span class=keybinding>Ctrl-Home (PC), Cmd-Up (Mac), Cmd-Home (Mac)</span>
            </dt>
            <dd>Move the cursor to the start of the document.</dd>

            <dt class=command id=command_goDocEnd><code><strong>goDocEnd</strong></code><span class=keybinding>Ctrl-End (PC), Cmd-End (Mac), Cmd-Down (Mac)</span>
            </dt>
            <dd>Move the cursor to the end of the document.</dd>

            <dt class=command id=command_goLineStart><code><strong>goLineStart</strong></code><span class=keybinding>Alt-Left (PC), Ctrl-A (Mac)</span>
            </dt>
            <dd>Move the cursor to the start of the line.</dd>

            <dt class=command id=command_goLineStartSmart><code><strong>goLineStartSmart</strong></code><span
                    class=keybinding>Home</span></dt>
            <dd>Move to the start of the text on the line, or if we are
                already there, to the actual start of the line (including
                whitespace).
            </dd>

            <dt class=command id=command_goLineEnd><code><strong>goLineEnd</strong></code><span class=keybinding>Alt-Right (PC), Ctrl-E (Mac)</span>
            </dt>
            <dd>Move the cursor to the end of the line.</dd>

            <dt class=command id=command_goLineRight><code><strong>goLineRight</strong></code><span class=keybinding>Cmd-Right (Mac)</span>
            </dt>
            <dd>Move the cursor to the right side of the visual line it is on.</dd>

            <dt class=command id=command_goLineLeft><code><strong>goLineLeft</strong></code><span class=keybinding>Cmd-Left (Mac)</span>
            </dt>
            <dd>Move the cursor to the left side of the visual line it is on. If
                this line is wrapped, that may not be the start of the line.
            </dd>

            <dt class=command id=command_goLineLeftSmart><code><strong>goLineLeftSmart</strong></code></dt>
            <dd>Move the cursor to the left side of the visual line it is
                on. If that takes it to the start of the line, behave
                like <a href="#command_goLineStartSmart"><code>goLineStartSmart</code></a>.
            </dd>

            <dt class=command id=command_goLineUp><code><strong>goLineUp</strong></code><span class=keybinding>Up, Ctrl-P (Mac)</span>
            </dt>
            <dd>Move the cursor up one line.</dd>

            <dt class=command id=command_goLineDown><code><strong>goLineDown</strong></code><span class=keybinding>Down, Ctrl-N (Mac)</span>
            </dt>
            <dd>Move down one line.</dd>

            <dt class=command id=command_goPageUp><code><strong>goPageUp</strong></code><span class=keybinding>PageUp, Shift-Ctrl-V (Mac)</span>
            </dt>
            <dd>Move the cursor up one screen, and scroll up by the same distance.</dd>

            <dt class=command id=command_goPageDown><code><strong>goPageDown</strong></code><span class=keybinding>PageDown, Ctrl-V (Mac)</span>
            </dt>
            <dd>Move the cursor down one screen, and scroll down by the same distance.</dd>

            <dt class=command id=command_goCharLeft><code><strong>goCharLeft</strong></code><span class=keybinding>Left, Ctrl-B (Mac)</span>
            </dt>
            <dd>Move the cursor one character left, going to the previous line
                when hitting the start of line.
            </dd>

            <dt class=command id=command_goCharRight><code><strong>goCharRight</strong></code><span class=keybinding>Right, Ctrl-F (Mac)</span>
            </dt>
            <dd>Move the cursor one character right, going to the next line
                when hitting the end of line.
            </dd>

            <dt class=command id=command_goColumnLeft><code><strong>goColumnLeft</strong></code></dt>
            <dd>Move the cursor one character left, but don't cross line boundaries.</dd>

            <dt class=command id=command_goColumnRight><code><strong>goColumnRight</strong></code></dt>
            <dd>Move the cursor one character right, don't cross line boundaries.</dd>

            <dt class=command id=command_goWordLeft><code><strong>goWordLeft</strong></code><span class=keybinding>Alt-B (Mac)</span>
            </dt>
            <dd>Move the cursor to the start of the previous word.</dd>

            <dt class=command id=command_goWordRight><code><strong>goWordRight</strong></code><span class=keybinding>Alt-F (Mac)</span>
            </dt>
            <dd>Move the cursor to the end of the next word.</dd>

            <dt class=command id=command_goGroupLeft><code><strong>goGroupLeft</strong></code><span class=keybinding>Ctrl-Left (PC), Alt-Left (Mac)</span>
            </dt>
            <dd>Move to the left of the group before the cursor. A group is
                a stretch of word characters, a stretch of punctuation
                characters, a newline, or a stretch of <em>more than one</em>
                whitespace character.
            </dd>

            <dt class=command id=command_goGroupRight><code><strong>goGroupRight</strong></code><span class=keybinding>Ctrl-Right (PC), Alt-Right (Mac)</span>
            </dt>
            <dd>Move to the right of the group after the cursor
                (see <a href="#command_goGroupLeft">above</a>).
            </dd>

            <dt class=command id=command_delCharBefore><code><strong>delCharBefore</strong></code><span
                    class=keybinding>Shift-Backspace, Ctrl-H (Mac)</span></dt>
            <dd>Delete the character before the cursor.</dd>

            <dt class=command id=command_delCharAfter><code><strong>delCharAfter</strong></code><span class=keybinding>Delete, Ctrl-D (Mac)</span>
            </dt>
            <dd>Delete the character after the cursor.</dd>

            <dt class=command id=command_delWordBefore><code><strong>delWordBefore</strong></code><span
                    class=keybinding>Alt-Backspace (Mac)</span></dt>
            <dd>Delete up to the start of the word before the cursor.</dd>

            <dt class=command id=command_delWordAfter><code><strong>delWordAfter</strong></code><span class=keybinding>Alt-D (Mac)</span>
            </dt>
            <dd>Delete up to the end of the word after the cursor.</dd>

            <dt class=command id=command_delGroupBefore><code><strong>delGroupBefore</strong></code><span
                    class=keybinding>Ctrl-Backspace (PC), Alt-Backspace (Mac)</span></dt>
            <dd>Delete to the left of the <a href="#command_goGroupLeft">group</a> before the cursor.</dd>

            <dt class=command id=command_delGroupAfter><code><strong>delGroupAfter</strong></code><span
                    class=keybinding>Ctrl-Delete (PC), Ctrl-Alt-Backspace (Mac), Alt-Delete (Mac)</span></dt>
            <dd>Delete to the start of the <a href="#command_goGroupLeft">group</a> after the cursor.</dd>

            <dt class=command id=command_indentAuto><code><strong>indentAuto</strong></code><span class=keybinding>Shift-Tab</span>
            </dt>
            <dd>Auto-indent the current line or selection.</dd>

            <dt class=command id=command_indentMore><code><strong>indentMore</strong></code><span class=keybinding>Ctrl-] (PC), Cmd-] (Mac)</span>
            </dt>
            <dd>Indent the current line or selection by one <a href="#option_indentUnit">indent unit</a>.</dd>

            <dt class=command id=command_indentLess><code><strong>indentLess</strong></code><span class=keybinding>Ctrl-[ (PC), Cmd-[ (Mac)</span>
            </dt>
            <dd>Dedent the current line or selection by one <a href="#option_indentUnit">indent unit</a>.</dd>

            <dt class=command id=command_insertTab><code><strong>insertTab</strong></code></dt>
            <dd>Insert a tab character at the cursor.</dd>

            <dt class=command id=command_insertSoftTab><code><strong>insertSoftTab</strong></code></dt>
            <dd>Insert the amount of spaces that match the width a tab at
                the cursor position would have.
            </dd>

            <dt class=command id=command_defaultTab><code><strong>defaultTab</strong></code><span
                    class=keybinding>Tab</span></dt>
            <dd>If something is selected, indent it by
                one <a href="#option_indentUnit">indent unit</a>. If nothing is
                selected, insert a tab character.
            </dd>

            <dt class=command id=command_transposeChars><code><strong>transposeChars</strong></code><span
                    class=keybinding>Ctrl-T (Mac)</span></dt>
            <dd>Swap the characters before and after the cursor.</dd>

            <dt class=command id=command_newlineAndIndent><code><strong>newlineAndIndent</strong></code><span
                    class=keybinding>Enter</span></dt>
            <dd>Insert a newline and auto-indent the new line.</dd>

            <dt class=command id=command_toggleOverwrite><code><strong>toggleOverwrite</strong></code><span
                    class=keybinding>Insert</span></dt>
            <dd>Flip the <a href="#toggleOverwrite">overwrite</a> flag.</dd>

            <dt class=command id=command_save><code><strong>save</strong></code><span class=keybinding>Ctrl-S (PC), Cmd-S (Mac)</span>
            </dt>
            <dd>Not defined by the core library, only referred to in
                key maps. Intended to provide an easy way for user code to define
                a save command.
            </dd>

            <dt class=command id=command_find><code><strong>find</strong></code><span class=keybinding>Ctrl-F (PC), Cmd-F (Mac)</span>
            </dt>
            <dt class=command id=command_findNext><code><strong>findNext</strong></code><span class=keybinding>Ctrl-G (PC), Cmd-G (Mac)</span>
            </dt>
            <dt class=command id=command_findPrev><code><strong>findPrev</strong></code><span class=keybinding>Shift-Ctrl-G (PC), Shift-Cmd-G (Mac)</span>
            </dt>
            <dt class=command id=command_replace><code><strong>replace</strong></code><span class=keybinding>Shift-Ctrl-F (PC), Cmd-Alt-F (Mac)</span>
            </dt>
            <dt class=command id=command_replaceAll><code><strong>replaceAll</strong></code><span class=keybinding>Shift-Ctrl-R (PC), Shift-Cmd-Alt-F (Mac)</span>
            </dt>
            <dd>Not defined by the core library, but defined in
                the <a href="#addon_search">search addon</a> (or custom client
                addons).
            </dd>

        </dl>

    </section>

    <section id=styling>
        <h2>Customized Styling</h2>

        <p>Up to a certain extent, CodeMirror's look can be changed by
            modifying style sheet files. The style sheets supplied by modes
            simply provide the colors for that mode, and can be adapted in a
            very straightforward way. To style the editor itself, it is
            possible to alter or override the styles defined
            in <a href="../lib/codemirror.css"><code>codemirror.css</code></a>.</p>

        <p>Some care must be taken there, since a lot of the rules in this
            file are necessary to have CodeMirror function properly. Adjusting
            colors should be safe, of course, and with some care a lot of
            other things can be changed as well. The CSS classes defined in
            this file serve the following roles:</p>

        <dl>
            <dt id="class_CodeMirror"><code><strong>CodeMirror</strong></code></dt>
            <dd>The outer element of the editor. This should be used for the
                editor width, height, borders and positioning. Can also be used
                to set styles that should hold for everything inside the editor
                (such as font and font size), or to set a background. Setting
                this class' <code>height</code> style to <code>auto</code> will
                make the editor <a href="../demo/resize.html">resize to fit its
                    content</a> (it is recommended to also set
                the <a href="#option_viewportMargin"><code>viewportMargin</code>
                    option</a> to <code>Infinity</code> when doing this.
            </dd>

            <dt id="class_CodeMirror_focused"><code><strong>CodeMirror-focused</strong></code></dt>
            <dd>Whenever the editor is focused, the top element gets this
                class. This is used to hide the cursor and give the selection a
                different color when the editor is not focused.
            </dd>

            <dt id="class_CodeMirror_gutters"><code><strong>CodeMirror-gutters</strong></code></dt>
            <dd>This is the backdrop for all gutters. Use it to set the
                default gutter background color, and optionally add a border on
                the right of the gutters.
            </dd>

            <dt id="class_CodeMirror_linenumbers"><code><strong>CodeMirror-linenumbers</strong></code></dt>
            <dd>Use this for giving a background or width to the line number
                gutter.
            </dd>

            <dt id="class_CodeMirror_linenumber"><code><strong>CodeMirror-linenumber</strong></code></dt>
            <dd>Used to style the actual individual line numbers. These
                won't be children of the <code>CodeMirror-linenumbers</code>
                (plural) element, but rather will be absolutely positioned to
                overlay it. Use this to set alignment and text properties for
                the line numbers.
            </dd>

            <dt id="class_CodeMirror_lines"><code><strong>CodeMirror-lines</strong></code></dt>
            <dd>The visible lines. This is where you specify vertical
                padding for the editor content.
            </dd>

            <dt id="class_CodeMirror_cursor"><code><strong>CodeMirror-cursor</strong></code></dt>
            <dd>The cursor is a block element that is absolutely positioned.
                You can make it look whichever way you want.
            </dd>

            <dt id="class_CodeMirror_selected"><code><strong>CodeMirror-selected</strong></code></dt>
            <dd>The selection is represented by <code>span</code> elements
                with this class.
            </dd>

            <dt id="class_CodeMirror_matchingbracket"><code><strong>CodeMirror-matchingbracket</strong></code>,
                <code><strong>CodeMirror-nonmatchingbracket</strong></code></dt>
            <dd>These are used to style matched (or unmatched) brackets.</dd>
        </dl>

        <p>If your page's style sheets do funky things to
            all <code>div</code> or <code>pre</code> elements (you probably
            shouldn't do that), you'll have to define rules to cancel these
            effects out again for elements under the <code>CodeMirror</code>
            class.</p>

        <p>Themes are also simply CSS files, which define colors for
            various syntactic elements. See the files in
            the <a href="../theme/"><code>theme</code></a> directory.</p>
    </section>

    <section id=api>
        <h2>Programming API</h2>

        <p>A lot of CodeMirror features are only available through its
            API. Thus, you need to write code (or
            use <a href="#addons">addons</a>) if you want to expose them to
            your users.</p>

        <p>Whenever points in the document are represented, the API uses
            objects with <code>line</code> and <code>ch</code> properties.
            Both are zero-based. CodeMirror makes sure to 'clip' any positions
            passed by client code so that they fit inside the document, so you
            shouldn't worry too much about sanitizing your coordinates. If you
            give <code>ch</code> a value of <code>null</code>, or don't
            specify it, it will be replaced with the length of the specified
            line. Such positions may also have a <code>sticky</code> property
            holding <code>"before"</code> or <code>"after"</code>, whether the
            position is associated with the character before or after it. This
            influences, for example, where the cursor is drawn on a
            line-break or bidi-direction boundary.</p>

        <p>Methods prefixed with <code>doc.</code> can, unless otherwise
            specified, be called both on <code>CodeMirror</code> (editor)
            instances and <code>CodeMirror.Doc</code> instances. Methods
            prefixed with <code>cm.</code> are <em>only</em> available
            on <code>CodeMirror</code> instances.</p>

        <h3 id="api_constructor">Constructor</h3>

        <p id="CodeMirror">Constructing an editor instance is done with
            the <code><strong>CodeMirror</strong>(place: Element|fn(Element),
                ?option: object)</code> constructor. If the <code>place</code>
            argument is a DOM element, the editor will be appended to it. If
            it is a function, it will be called, and is expected to place the
            editor into the document. <code>options</code> may be an element
            mapping <a href="#config">option names</a> to values. The options
            that it doesn't explicitly specify (or all options, if it is not
            passed) will be taken
            from <a href="#defaults"><code>CodeMirror.defaults</code></a>.</p>

        <p>Note that the options object passed to the constructor will be
            mutated when the instance's options
            are <a href="#setOption">changed</a>, so you shouldn't share such
            objects between instances.</p>

        <p>See <a href="#fromTextArea"><code>CodeMirror.fromTextArea</code></a>
            for another way to construct an editor instance.</p>

        <h3 id="api_content">Content manipulation methods</h3>

        <dl>
            <dt id="getValue"><code><strong>doc.getValue</strong>(?separator: string) → string</code></dt>
            <dd>Get the current editor content. You can pass it an optional
                argument to specify the string to be used to separate lines
                (defaults to <code>"\n"</code>).
            </dd>
            <dt id="setValue"><code><strong>doc.setValue</strong>(content: string)</code></dt>
            <dd>Set the editor content.</dd>

            <dt id="getRange"><code><strong>doc.getRange</strong>(from: {line, ch}, to: {line, ch}, ?separator: string)
                → string</code></dt>
            <dd>Get the text between the given points in the editor, which
                should be <code>{line, ch}</code> objects. An optional third
                argument can be given to indicate the line separator string to
                use (defaults to <code>"\n"</code>).
            </dd>
            <dt id="replaceRange"><code><strong>doc.replaceRange</strong>(replacement: string, from: {line, ch},
                to: {line, ch}, ?origin: string)</code></dt>
            <dd>Replace the part of the document between <code>from</code>
                and <code>to</code> with the given string. <code>from</code>
                and <code>to</code> must be <code>{line, ch}</code>
                objects. <code>to</code> can be left off to simply insert the
                string at position <code>from</code>. When <code>origin</code>
                is given, it will be passed on
                to <a href="#event_change"><code>"change"</code> events</a>, and
                its first letter will be used to determine whether this change
                can be merged with previous history events, in the way described
                for <a href="#selection_origin">selection origins</a>.
            </dd>

            <dt id="getLine"><code><strong>doc.getLine</strong>(n: integer) → string</code></dt>
            <dd>Get the content of line <code>n</code>.</dd>

            <dt id="lineCount"><code><strong>doc.lineCount</strong>() → integer</code></dt>
            <dd>Get the number of lines in the editor.</dd>
            <dt id="firstLine"><code><strong>doc.firstLine</strong>() → integer</code></dt>
            <dd>Get the number of first line in the editor. This will
                usually be zero but for <a href="#linkedDoc_from">linked sub-views</a>,
                or <a href="#api_doc">documents</a> instantiated with a non-zero
                first line, it might return other values.
            </dd>
            <dt id="lastLine"><code><strong>doc.lastLine</strong>() → integer</code></dt>
            <dd>Get the number of last line in the editor. This will
                usually be <code>doc.lineCount() - 1</code>,
                but for <a href="#linkedDoc_from">linked sub-views</a>,
                it might return other values.
            </dd>

            <dt id="getLineHandle"><code><strong>doc.getLineHandle</strong>(num: integer) → LineHandle</code></dt>
            <dd>Fetches the line handle for the given line number.</dd>
            <dt id="getLineNumber"><code><strong>doc.getLineNumber</strong>(handle: LineHandle) → integer</code></dt>
            <dd>Given a line handle, returns the current position of that
                line (or <code>null</code> when it is no longer in the
                document).
            </dd>
            <dt id="eachLine"><code><strong>doc.eachLine</strong>(f: (line: LineHandle))</code></dt>
            <dt><code><strong>doc.eachLine</strong>(start: integer, end: integer, f: (line: LineHandle))</code></dt>
            <dd>Iterate over the whole document, or if <code>start</code>
                and <code>end</code> line numbers are given, the range
                from <code>start</code> up to (not including) <code>end</code>,
                and call <code>f</code> for each line, passing the line handle.
                This is a faster way to visit a range of line handlers than
                calling <a href="#getLineHandle"><code>getLineHandle</code></a>
                for each of them. Note that line handles have
                a <code>text</code> property containing the line's content (as a
                string).
            </dd>

            <dt id="markClean"><code><strong>doc.markClean</strong>()</code></dt>
            <dd>Set the editor content as 'clean', a flag that it will
                retain until it is edited, and which will be set again when such
                an edit is undone again. Useful to track whether the content
                needs to be saved. This function is deprecated in favor
                of <a href="#changeGeneration"><code>changeGeneration</code></a>,
                which allows multiple subsystems to track different notions of
                cleanness without interfering.
            </dd>
            <dt id="changeGeneration"><code><strong>doc.changeGeneration</strong>(?closeEvent: boolean) → integer</code>
            </dt>
            <dd>Returns a number that can later be passed
                to <a href="#isClean"><code>isClean</code></a> to test whether
                any edits were made (and not undone) in the meantime.
                If <code>closeEvent</code> is true, the current history event
                will be ‘closed’, meaning it can't be combined with further
                changes (rapid typing or deleting events are typically
                combined).
            </dd>
            <dt id="isClean"><code><strong>doc.isClean</strong>(?generation: integer) → boolean</code></dt>
            <dd>Returns whether the document is currently clean — not
                modified since initialization or the last call
                to <a href="#markClean"><code>markClean</code></a> if no
                argument is passed, or since the matching call
                to <a href="#changeGeneration"><code>changeGeneration</code></a>
                if a generation value is given.
            </dd>
        </dl>

        <h3 id="api_selection">Cursor and selection methods</h3>

        <dl>
            <dt id="getSelection"><code><strong>doc.getSelection</strong>(?lineSep: string) → string</code></dt>
            <dd>Get the currently selected code. Optionally pass a line
                separator to put between the lines in the output. When multiple
                selections are present, they are concatenated with instances
                of <code>lineSep</code> in between.
            </dd>
            <dt id="getSelections"><code><strong>doc.getSelections</strong>(?lineSep: string) →
                array&lt;string&gt;</code></dt>
            <dd>Returns an array containing a string for each selection,
                representing the content of the selections.
            </dd>

            <dt id="replaceSelection"><code><strong>doc.replaceSelection</strong>(replacement: string, ?select: string)</code>
            </dt>
            <dd>Replace the selection(s) with the given string. By default,
                the new selection ends up after the inserted text. The
                optional <code>select</code> argument can be used to change
                this—passing <code>"around"</code> will cause the new text to be
                selected, passing <code>"start"</code> will collapse the
                selection to the start of the inserted text.
            </dd>
            <dt id="replaceSelections"><code><strong>doc.replaceSelections</strong>(replacements: array&lt;string&gt;,
                ?select: string)</code></dt>
            <dd>The length of the given array should be the same as the
                number of active selections. Replaces the content of the
                selections with the strings in the array.
                The <code>select</code> argument works the same as
                in <a href="#replaceSelection"><code>replaceSelection</code></a>.
            </dd>

            <dt id="getCursor"><code><strong>doc.getCursor</strong>(?start: string) → {line, ch}</code></dt>
            <dd>Retrieve one end of the <em>primary</em>
                selection. <code>start</code> is an optional string indicating
                which end of the selection to return. It may
                be <code>"from"</code>, <code>"to"</code>, <code>"head"</code>
                (the side of the selection that moves when you press
                shift+arrow), or <code>"anchor"</code> (the fixed side of the
                selection). Omitting the argument is the same as
                passing <code>"head"</code>. A <code>{line, ch}</code> object
                will be returned.
            </dd>
            <dt id="listSelections"><code><strong>doc.listSelections</strong>() → array&lt;{anchor, head}&gt;</code>
            </dt>
            <dd>Retrieves a list of all current selections. These will
                always be sorted, and never overlap (overlapping selections are
                merged). Each object in the array contains <code>anchor</code>
                and <code>head</code> properties referring to <code>{line,
                    ch}</code> objects.
            </dd>

            <dt id="somethingSelected"><code><strong>doc.somethingSelected</strong>() → boolean</code></dt>
            <dd>Return true if any text is selected.</dd>
            <dt id="setCursor"><code><strong>doc.setCursor</strong>(pos: {line, ch}|number, ?ch: number, ?options:
                object)</code></dt>
            <dd>Set the cursor position. You can either pass a
                single <code>{line, ch}</code> object, or the line and the
                character as two separate parameters. Will replace all
                selections with a single, empty selection at the given position.
                The supported options are the same as for <a href="#setSelection"><code>setSelection</code></a>.
            </dd>

            <dt id="setSelection"><code><strong>doc.setSelection</strong>(anchor: {line, ch}, ?head: {line, ch},
                ?options: object)</code></dt>
            <dd>Set a single selection range. <code>anchor</code>
                and <code>head</code> should be <code>{line, ch}</code>
                objects. <code>head</code> defaults to <code>anchor</code> when
                not given. These options are supported:
                <dl>
                    <dt id="selection_scroll"><code><strong>scroll</strong>: boolean</code></dt>
                    <dd>Determines whether the selection head should be scrolled
                        into view. Defaults to true.
                    </dd>
                    <dt id="selection_origin"><code><strong>origin</strong>: string</code></dt>
                    <dd>Determines whether the selection history event may be
                        merged with the previous one. When an origin starts with the
                        character <code>+</code>, and the last recorded selection had
                        the same origin and was similar (close
                        in <a href="#option_historyEventDelay">time</a>, both
                        collapsed or both non-collapsed), the new one will replace the
                        old one. When it starts with <code>*</code>, it will always
                        replace the previous event (if that had the same origin).
                        Built-in motion uses the <code>"+move"</code> origin. User input uses the <code>"+input"</code>
                        origin.
                    </dd>
                    <dt id="selection_bias"><code><strong>bias</strong>: number</code></dt>
                    <dd>Determine the direction into which the selection endpoints
                        should be adjusted when they fall inside
                        an <a href="#mark_atomic">atomic</a> range. Can be either -1
                        (backward) or 1 (forward). When not given, the bias will be
                        based on the relative position of the old selection—the editor
                        will try to move further away from that, to prevent getting
                        stuck.
                    </dd>
                </dl>
            </dd>

            <dt id="setSelections"><code><strong>doc.setSelections</strong>(ranges: array&lt;{anchor, head}&gt;,
                ?primary: integer, ?options: object)</code></dt>
            <dd>Sets a new set of selections. There must be at least one
                selection in the given array. When <code>primary</code> is a
                number, it determines which selection is the primary one. When
                it is not given, the primary index is taken from the previous
                selection, or set to the last range if the previous selection
                had less ranges than the new one. Supports the same options
                as <a href="#setSelection"><code>setSelection</code></a>.
            </dd>
            <dt id="addSelection"><code><strong>doc.addSelection</strong>(anchor: {line, ch}, ?head: {line, ch})</code>
            </dt>
            <dd>Adds a new selection to the existing set of selections, and
                makes it the primary selection.
            </dd>

            <dt id="extendSelection"><code><strong>doc.extendSelection</strong>(from: {line, ch}, ?to: {line, ch},
                ?options: object)</code></dt>
            <dd>Similar
                to <a href="#setSelection"><code>setSelection</code></a>, but
                will, if shift is held or
                the <a href="#setExtending">extending</a> flag is set, move the
                head of the selection while leaving the anchor at its current
                place. <code>to</code> is optional, and can be passed to ensure
                a region (for example a word or paragraph) will end up selected
                (in addition to whatever lies between that region and the
                current anchor). When multiple selections are present, all but
                the primary selection will be dropped by this method.
                Supports the same options as <a href="#setSelection"><code>setSelection</code></a>.
            </dd>
            <dt id="extendSelections"><code><strong>doc.extendSelections</strong>(heads: array&lt;{line, ch}&gt;,
                ?options: object)</code></dt>
            <dd>An equivalent
                of <a href="#extendSelection"><code>extendSelection</code></a>
                that acts on all selections at once.
            </dd>
            <dt id="extendSelectionsBy"><code><strong>doc.extendSelectionsBy</strong>(f: function(range: {anchor, head})
                → {line, ch}), ?options: object)</code></dt>
            <dd>Applies the given function to all existing selections, and
                calls <a href="#extendSelections"><code>extendSelections</code></a>
                on the result.
            </dd>
            <dt id="setExtending"><code><strong>doc.setExtending</strong>(value: boolean)</code></dt>
            <dd>Sets or clears the 'extending' flag, which acts similar to
                the shift key, in that it will cause cursor movement and calls
                to <a href="#extendSelection"><code>extendSelection</code></a>
                to leave the selection anchor in place.
            </dd>
            <dt id="getExtending"><code><strong>doc.getExtending</strong>() → boolean</code></dt>
            <dd>Get the value of the 'extending' flag.</dd>

            <dt id="hasFocus"><code><strong>cm.hasFocus</strong>() → boolean</code></dt>
            <dd>Tells you whether the editor currently has focus.</dd>

            <dt id="findPosH"><code><strong>cm.findPosH</strong>(start: {line, ch}, amount: integer, unit: string,
                visually: boolean) → {line, ch, ?hitSide: boolean}</code></dt>
            <dd>Used to find the target position for horizontal cursor
                motion. <code>start</code> is a <code>{line, ch}</code>
                object, <code>amount</code> an integer (may be negative),
                and <code>unit</code> one of the
                string <code>"char"</code>, <code>"column"</code>,
                or <code>"word"</code>. Will return a position that is produced
                by moving <code>amount</code> times the distance specified
                by <code>unit</code>. When <code>visually</code> is true, motion
                in right-to-left text will be visual rather than logical. When
                the motion was clipped by hitting the end or start of the
                document, the returned value will have a <code>hitSide</code>
                property set to true.
            </dd>
            <dt id="findPosV"><code><strong>cm.findPosV</strong>(start: {line, ch}, amount: integer, unit: string) →
                {line, ch, ?hitSide: boolean}</code></dt>
            <dd>Similar to <a href="#findPosH"><code>findPosH</code></a>,
                but used for vertical motion. <code>unit</code> may
                be <code>"line"</code> or <code>"page"</code>. The other
                arguments and the returned value have the same interpretation as
                they have in <code>findPosH</code>.
            </dd>

            <dt id="findWordAt"><code><strong>cm.findWordAt</strong>(pos: {line, ch}) → {anchor: {line, ch}, head:
                {line, ch}}</code></dt>
            <dd>Returns the start and end of the 'word' (the stretch of
                letters, whitespace, or punctuation) at the given position.
            </dd>
        </dl>

        <h3 id="api_configuration">Configuration methods</h3>

        <dl>
            <dt id="setOption"><code><strong>cm.setOption</strong>(option: string, value: any)</code></dt>
            <dd>Change the configuration of the editor. <code>option</code>
                should the name of an <a href="#config">option</a>,
                and <code>value</code> should be a valid value for that
                option.
            </dd>
            <dt id="getOption"><code><strong>cm.getOption</strong>(option: string) → any</code></dt>
            <dd>Retrieves the current value of the given option for this
                editor instance.
            </dd>

            <dt id="addKeyMap"><code><strong>cm.addKeyMap</strong>(map: object, bottom: boolean)</code></dt>
            <dd>Attach an additional <a href="#keymaps">key map</a> to the
                editor. This is mostly useful for addons that need to register
                some key handlers without trampling on
                the <a href="#option_extraKeys"><code>extraKeys</code></a>
                option. Maps added in this way have a higher precedence than
                the <code>extraKeys</code>
                and <a href="#option_keyMap"><code>keyMap</code></a> options,
                and between them, the maps added earlier have a lower precedence
                than those added later, unless the <code>bottom</code> argument
                was passed, in which case they end up below other key maps added
                with this method.
            </dd>
            <dt id="removeKeyMap"><code><strong>cm.removeKeyMap</strong>(map: object)</code></dt>
            <dd>Disable a keymap added
                with <a href="#addKeyMap"><code>addKeyMap</code></a>. Either
                pass in the key map object itself, or a string, which will be
                compared against the <code>name</code> property of the active
                key maps.
            </dd>

            <dt id="addOverlay"><code><strong>cm.addOverlay</strong>(mode: string|object, ?options: object)</code></dt>
            <dd>Enable a highlighting overlay. This is a stateless mini-mode
                that can be used to add extra highlighting. For example,
                the <a href="../demo/search.html">search addon</a> uses it to
                highlight the term that's currently being
                searched. <code>mode</code> can be a <a href="#option_mode">mode
                    spec</a> or a mode object (an object with
                a <a href="#token"><code>token</code></a> method).
                The <code>options</code> parameter is optional. If given, it
                should be an object, optionally containing the following options:
                <dl>
                    <dt><code><strong>opaque</strong>: bool</code></dt>
                    <dd>Defaults to off, but can be given to allow the overlay
                        styling, when not <code>null</code>, to override the styling of
                        the base mode entirely, instead of the two being applied
                        together.
                    </dd>
                    <dt><code><strong>priority</strong>: number</code></dt>
                    <dd>Determines the ordering in which the overlays are
                        applied. Those with high priority are applied after those
                        with lower priority, and able to override the opaqueness of
                        the ones that come before. Defaults to 0.
                    </dd>
                </dl>
            </dd>

            <dt id="removeOverlay"><code><strong>cm.removeOverlay</strong>(mode: string|object)</code></dt>
            <dd>Pass this the exact value passed for the <code>mode</code>
                parameter to <a href="#addOverlay"><code>addOverlay</code></a>,
                or a string that corresponds to the <code>name</code> property of
                that value, to remove an overlay again.
            </dd>

            <dt id="on"><code><strong>cm.on</strong>(type: string, func: (...args))</code></dt>
            <dd>Register an event handler for the given event type (a
                string) on the editor instance. There is also
                a <code>CodeMirror.on(object, type, func)</code> version
                that allows registering of events on any object.
            </dd>
            <dt id="off"><code><strong>cm.off</strong>(type: string, func: (...args))</code></dt>
            <dd>Remove an event handler on the editor instance. An
                equivalent <code>CodeMirror.off(object, type,
                    func)</code> also exists.
            </dd>
        </dl>

        <h3 id="api_doc">Document management methods</h3>

        <p id="Doc">Each editor is associated with an instance
            of <code>CodeMirror.Doc</code>, its document. A document
            represents the editor content, plus a selection, an undo history,
            and a <a href="#option_mode">mode</a>. A document can only be
            associated with a single editor at a time. You can create new
            documents by calling the <code>CodeMirror.Doc(text: string, mode:
                Object, firstLineNumber: ?number, lineSeparator: ?string)</code>
            constructor. The last three arguments are optional and can be used
            to set a mode for the document, make it start at a line number
            other than 0, and set a specific line separator respectively.</p>

        <dl>
            <dt id="getDoc"><code><strong>cm.getDoc</strong>() → Doc</code></dt>
            <dd>Retrieve the currently active document from an editor.</dd>
            <dt id="getEditor"><code><strong>doc.getEditor</strong>() → CodeMirror</code></dt>
            <dd>Retrieve the editor associated with a document. May
                return <code>null</code>.
            </dd>

            <dt id="swapDoc"><code><strong>cm.swapDoc</strong>(doc: CodeMirror.Doc) → Doc</code></dt>
            <dd>Attach a new document to the editor. Returns the old
                document, which is now no longer associated with an editor.
            </dd>

            <dt id="copy"><code><strong>doc.copy</strong>(copyHistory: boolean) → Doc</code></dt>
            <dd>Create an identical copy of the given doc.
                When <code>copyHistory</code> is true, the history will also be
                copied. Can not be called directly on an editor.
            </dd>

            <dt id="linkedDoc"><code><strong>doc.linkedDoc</strong>(options: object) → Doc</code></dt>
            <dd>Create a new document that's linked to the target document.
                Linked documents will stay in sync (changes to one are also
                applied to the other) until <a href="#unlinkDoc">unlinked</a>.
                These are the options that are supported:
                <dl>
                    <dt id="linkedDoc_sharedHist"><code><strong>sharedHist</strong>: boolean</code></dt>
                    <dd>When turned on, the linked copy will share an undo
                        history with the original. Thus, something done in one of
                        the two can be undone in the other, and vice versa.
                    </dd>
                    <dt id="linkedDoc_from"><code><strong>from</strong>: integer</code></dt>
                    <dt id="linkedDoc_to"><code><strong>to</strong>: integer</code></dt>
                    <dd>Can be given to make the new document a subview of the
                        original. Subviews only show a given range of lines. Note
                        that line coordinates inside the subview will be consistent
                        with those of the parent, so that for example a subview
                        starting at line 10 will refer to its first line as line 10,
                        not 0.
                    </dd>
                    <dt id="linkedDoc_mode"><code><strong>mode</strong>: string|object</code></dt>
                    <dd>By default, the new document inherits the mode of the
                        parent. This option can be set to
                        a <a href="#option_mode">mode spec</a> to give it a
                        different mode.
                    </dd>
                </dl>
            </dd>
            <dt id="unlinkDoc"><code><strong>doc.unlinkDoc</strong>(doc: CodeMirror.Doc)</code></dt>
            <dd>Break the link between two documents. After calling this,
                changes will no longer propagate between the documents, and, if
                they had a shared history, the history will become
                separate.
            </dd>
            <dt id="iterLinkedDocs"><code><strong>doc.iterLinkedDocs</strong>(function: (doc: CodeMirror.Doc,
                sharedHist: boolean))</code></dt>
            <dd>Will call the given function for all documents linked to the
                target document. It will be passed two arguments, the linked document
                and a boolean indicating whether that document shares history
                with the target.
            </dd>
        </dl>

        <h3 id="api_history">History-related methods</h3>

        <dl>
            <dt id="undo"><code><strong>doc.undo</strong>()</code></dt>
            <dd>Undo one edit (if any undo events are stored).</dd>
            <dt id="redo"><code><strong>doc.redo</strong>()</code></dt>
            <dd>Redo one undone edit.</dd>

            <dt id="undoSelection"><code><strong>doc.undoSelection</strong>()</code></dt>
            <dd>Undo one edit or selection change.</dd>
            <dt id="redoSelection"><code><strong>doc.redoSelection</strong>()</code></dt>
            <dd>Redo one undone edit or selection change.</dd>

            <dt id="historySize"><code><strong>doc.historySize</strong>() → {undo: integer, redo: integer}</code></dt>
            <dd>Returns an object with <code>{undo, redo}</code> properties,
                both of which hold integers, indicating the amount of stored
                undo and redo operations.
            </dd>
            <dt id="clearHistory"><code><strong>doc.clearHistory</strong>()</code></dt>
            <dd>Clears the editor's undo history.</dd>
            <dt id="getHistory"><code><strong>doc.getHistory</strong>() → object</code></dt>
            <dd>Get a (JSON-serializable) representation of the undo history.</dd>
            <dt id="setHistory"><code><strong>doc.setHistory</strong>(history: object)</code></dt>
            <dd>Replace the editor's undo history with the one provided,
                which must be a value as returned
                by <a href="#getHistory"><code>getHistory</code></a>. Note that
                this will have entirely undefined results if the editor content
                isn't also the same as it was when <code>getHistory</code> was
                called.
            </dd>
        </dl>

        <h3 id="api_marker">Text-marking methods</h3>

        <dl>
            <dt id="markText"><code><strong>doc.markText</strong>(from: {line, ch}, to: {line, ch}, ?options: object) →
                TextMarker</code></dt>
            <dd>Can be used to mark a range of text with a specific CSS
                class name. <code>from</code> and <code>to</code> should
                be <code>{line, ch}</code> objects. The <code>options</code>
                parameter is optional. When given, it should be an object that
                may contain the following configuration options:
                <dl>
                    <dt id="mark_className"><code><strong>className</strong>: string</code></dt>
                    <dd>Assigns a CSS class to the marked stretch of text.</dd>
                    <dt id="mark_inclusiveLeft"><code><strong>inclusiveLeft</strong>: boolean</code></dt>
                    <dd>Determines whether
                        text inserted on the left of the marker will end up inside
                        or outside of it.
                    </dd>
                    <dt id="mark_inclusiveRight"><code><strong>inclusiveRight</strong>: boolean</code></dt>
                    <dd>Like <code>inclusiveLeft</code>,
                        but for the right side.
                    </dd>
                    <dt id="mark_selectLeft"><code><strong>selectLeft</strong>: boolean</code></dt>
                    <dd>For atomic ranges, determines whether the cursor is allowed
                        to be placed directly to the left of the range. Has no effect on
                        non-atomic ranges.
                    </dd>
                    <dt id="mark_selectRight"><code><strong>selectRight</strong>: boolean</code></dt>
                    <dd>Like <code>selectLeft</code>,
                        but for the right side.
                    </dd>
                    <dt id="mark_atomic"><code><strong>atomic</strong>: boolean</code></dt>
                    <dd>Atomic ranges act as a single unit when cursor movement is
                        concerned—i.e. it is impossible to place the cursor inside of
                        them. You can control whether the cursor is allowed to be placed
                        directly before or after them using <code>selectLeft</code>
                        or <code>selectRight</code>. If <code>selectLeft</code>
                        (or right) is not provided, then <code>inclusiveLeft</code> (or
                        right) will control this behavior.
                    </dd>
                    <dt id="mark_collapsed"><code><strong>collapsed</strong>: boolean</code></dt>
                    <dd>Collapsed ranges do not show up in the display. Setting a
                        range to be collapsed will automatically make it atomic.
                    </dd>
                    <dt id="mark_clearOnEnter"><code><strong>clearOnEnter</strong>: boolean</code></dt>
                    <dd>When enabled, will cause the mark to clear itself whenever
                        the cursor enters its range. This is mostly useful for
                        text-replacement widgets that need to 'snap open' when the
                        user tries to edit them. The
                        <a href="#event_clear"><code>"clear"</code></a> event
                        fired on the range handle can be used to be notified when this
                        happens.
                    </dd>
                    <dt id="mark_clearWhenEmpty"><code><strong>clearWhenEmpty</strong>: boolean</code></dt>
                    <dd>Determines whether the mark is automatically cleared when
                        it becomes empty. Default is true.
                    </dd>
                    <dt id="mark_replacedWith"><code><strong>replacedWith</strong>: Element</code></dt>
                    <dd>Use a given node to display this range. Implies both
                        collapsed and atomic. The given DOM node <em>must</em> be an
                        inline element (as opposed to a block element).
                    </dd>
                    <dt><code><strong>handleMouseEvents</strong>: boolean</code></dt>
                    <dd>When <code>replacedWith</code> is given, this determines
                        whether the editor will capture mouse and drag events
                        occurring in this widget. Default is false—the events will be
                        left alone for the default browser handler, or specific
                        handlers on the widget, to capture.
                    </dd>
                    <dt id="mark_readOnly"><code><strong>readOnly</strong>: boolean</code></dt>
                    <dd>A read-only span can, as long as it is not cleared, not be
                        modified except by
                        calling <a href="#setValue"><code>setValue</code></a> to reset
                        the whole document. <em>Note:</em> adding a read-only span
                        currently clears the undo history of the editor, because
                        existing undo events being partially nullified by read-only
                        spans would corrupt the history (in the current
                        implementation).
                    </dd>
                    <dt id="mark_addToHistory"><code><strong>addToHistory</strong>: boolean</code></dt>
                    <dd>When set to true (default is false), adding this marker
                        will create an event in the undo history that can be
                        individually undone (clearing the marker).
                    </dd>
                    <dt id="mark_startStyle"><code><strong>startStyle</strong>: string</code></dt>
                    <dd>Can be used to specify
                        an extra CSS class to be applied to the leftmost span that
                        is part of the marker.
                    </dd>
                    <dt id="mark_endStyle"><code><strong>endStyle</strong>: string</code></dt>
                    <dd>Equivalent
                        to <code>startStyle</code>, but for the rightmost span.
                    </dd>
                    <dt id="mark_css"><code><strong>css</strong>: string</code></dt>
                    <dd>A string of CSS to be applied to the covered text. For example <code>"color: #fe3"</code>.</dd>
                    <dt id="mark_attributes"><code><strong>attributes</strong>: object</code></dt>
                    <dd>When given, add the attributes in the given object to the
                        elements created for the marked text. Adding <code>class</code> or
                        <code>style</code> attributes this way is not supported.
                    </dd>
                    <dt id="mark_shared"><code><strong>shared</strong>: boolean</code></dt>
                    <dd>When the
                        target document is <a href="#linkedDoc">linked</a> to other
                        documents, you can set <code>shared</code> to true to make the
                        marker appear in all documents. By default, a marker appears
                        only in its target document.
                    </dd>
                </dl>
                The method will return an object that represents the marker
                (with constructor <code>CodeMirror.TextMarker</code>), which
                exposes three methods:
                <code><strong>clear</strong>()</code>, to remove the mark,
                <code><strong>find</strong>()</code>, which returns
                a <code>{from, to}</code> object (both holding document
                positions), indicating the current position of the marked range,
                or <code>undefined</code> if the marker is no longer in the
                document, and finally <code><strong>changed</strong>()</code>,
                which you can call if you've done something that might change
                the size of the marker (for example changing the content of
                a <a href="#mark_replacedWith"><code>replacedWith</code></a>
                node), and want to cheaply update the display.
            </dd>

            <dt id="setBookmark"><code><strong>doc.setBookmark</strong>(pos: {line, ch}, ?options: object) → TextMarker</code>
            </dt>
            <dd>Inserts a bookmark, a handle that follows the text around it
                as it is being edited, at the given position. A bookmark has two
                methods <code>find()</code> and <code>clear()</code>. The first
                returns the current position of the bookmark, if it is still in
                the document, and the second explicitly removes the bookmark.
                The options argument is optional. If given, the following
                properties are recognized:
                <dl>
                    <dt><code><strong>widget</strong>: Element</code></dt>
                    <dd>Can be used to display a DOM
                        node at the current location of the bookmark (analogous to
                        the <a href="#mark_replacedWith"><code>replacedWith</code></a>
                        option to <a href="#markText"><code>markText</code></a>).
                    </dd>
                    <dt><code><strong>insertLeft</strong>: boolean</code></dt>
                    <dd>By default, text typed
                        when the cursor is on top of the bookmark will end up to the
                        right of the bookmark. Set this option to true to make it go
                        to the left instead.
                    </dd>
                    <dt><code><strong>shared</strong>: boolean</code></dt>
                    <dd>See
                        the corresponding <a href="#mark_shared">option</a>
                        to <code>markText</code>.
                    </dd>
                    <dt><code><strong>handleMouseEvents</strong>: boolean</code></dt>
                    <dd>As with <a href="#markText"><code>markText</code></a>,
                        this determines whether mouse events on the widget inserted
                        for this bookmark are handled by CodeMirror. The default is
                        false.
                    </dd>
                </dl>
            </dd>

            <dt id="findMarks"><code><strong>doc.findMarks</strong>(from: {line, ch}, to: {line, ch}) → array&lt;TextMarker&gt;</code>
            </dt>
            <dd>Returns an array of all the bookmarks and marked ranges
                found between the given positions (non-inclusive).
            </dd>
            <dt id="findMarksAt"><code><strong>doc.findMarksAt</strong>(pos: {line, ch}) →
                array&lt;TextMarker&gt;</code></dt>
            <dd>Returns an array of all the bookmarks and marked ranges
                present at the given position.
            </dd>
            <dt id="getAllMarks"><code><strong>doc.getAllMarks</strong>() → array&lt;TextMarker&gt;</code></dt>
            <dd>Returns an array containing all marked ranges in the document.</dd>
        </dl>

        <h3 id="api_decoration">Widget, gutter, and decoration methods</h3>

        <dl>
            <dt id="setGutterMarker"><code><strong>doc.setGutterMarker</strong>(line: integer|LineHandle, gutterID:
                string, value: Element) → LineHandle</code></dt>
            <dd>Sets the gutter marker for the given gutter (identified by
                its CSS class, see
                the <a href="#option_gutters"><code>gutters</code></a> option)
                to the given value. Value can be either <code>null</code>, to
                clear the marker, or a DOM element, to set it. The DOM element
                will be shown in the specified gutter next to the specified
                line.
            </dd>

            <dt id="clearGutter"><code><strong>doc.clearGutter</strong>(gutterID: string)</code></dt>
            <dd>Remove all gutter markers in
                the <a href="#option_gutters">gutter</a> with the given ID.
            </dd>

            <dt id="addLineClass"><code><strong>doc.addLineClass</strong>(line: integer|LineHandle, where: string,
                class: string) → LineHandle</code></dt>
            <dd>Set a CSS class name for the given line. <code>line</code>
                can be a number or a line handle. <code>where</code> determines
                to which element this class should be applied, can can be one
                of <code>"text"</code> (the text element, which lies in front of
                the selection), <code>"background"</code> (a background element
                that will be behind the selection), <code>"gutter"</code> (the
                line's gutter space), or <code>"wrap"</code> (the wrapper node
                that wraps all of the line's elements, including gutter
                elements). <code>class</code> should be the name of the class to
                apply.
            </dd>

            <dt id="removeLineClass"><code><strong>doc.removeLineClass</strong>(line: integer|LineHandle, where: string,
                class: string) → LineHandle</code></dt>
            <dd>Remove a CSS class from a line. <code>line</code> can be a
                line handle or number. <code>where</code> should be one
                of <code>"text"</code>, <code>"background"</code>,
                or <code>"wrap"</code>
                (see <a href="#addLineClass"><code>addLineClass</code></a>). <code>class</code>
                can be left off to remove all classes for the specified node, or
                be a string to remove only a specific class.
            </dd>

            <dt id="lineInfo"><code><strong>doc.lineInfo</strong>(line: integer|LineHandle) → object</code></dt>
            <dd>Returns the line number, text content, and marker status of
                the given line, which can be either a number or a line handle.
                The returned object has the structure <code>{line, handle, text,
                    gutterMarkers, textClass, bgClass, wrapClass, widgets}</code>,
                where <code>gutterMarkers</code> is an object mapping gutter IDs
                to marker elements, and <code>widgets</code> is an array
                of <a href="#addLineWidget">line widgets</a> attached to this
                line, and the various class properties refer to classes added
                with <a href="#addLineClass"><code>addLineClass</code></a>.
            </dd>

            <dt id="addWidget"><code><strong>cm.addWidget</strong>(pos: {line, ch}, node: Element, scrollIntoView:
                boolean)</code></dt>
            <dd>Puts <code>node</code>, which should be an absolutely
                positioned DOM node, into the editor, positioned right below the
                given <code>{line, ch}</code> position.
                When <code>scrollIntoView</code> is true, the editor will ensure
                that the entire node is visible (if possible). To remove the
                widget again, simply use DOM methods (move it somewhere else, or
                call <code>removeChild</code> on its parent).
            </dd>

            <dt id="addLineWidget"><code><strong>doc.addLineWidget</strong>(line: integer|LineHandle, node: Element,
                ?options: object) → LineWidget</code></dt>
            <dd>Adds a line widget, an element shown below a line, spanning
                the whole of the editor's width, and moving the lines below it
                downwards. <code>line</code> should be either an integer or a
                line handle, and <code>node</code> should be a DOM node, which
                will be displayed below the given line. <code>options</code>,
                when given, should be an object that configures the behavior of
                the widget. The following options are supported (all default to
                false):
                <dl>
                    <dt><code><strong>coverGutter</strong>: boolean</code></dt>
                    <dd>Whether the widget should cover the gutter.</dd>
                    <dt><code><strong>noHScroll</strong>: boolean</code></dt>
                    <dd>Whether the widget should stay fixed in the face of
                        horizontal scrolling.
                    </dd>
                    <dt><code><strong>above</strong>: boolean</code></dt>
                    <dd>Causes the widget to be placed above instead of below
                        the text of the line.
                    </dd>
                    <dt><code><strong>handleMouseEvents</strong>: boolean</code></dt>
                    <dd>Determines whether the editor will capture mouse and
                        drag events occurring in this widget. Default is false—the
                        events will be left alone for the default browser handler,
                        or specific handlers on the widget, to capture.
                    </dd>
                    <dt><code><strong>insertAt</strong>: integer</code></dt>
                    <dd>By default, the widget is added below other widgets for
                        the line. This option can be used to place it at a different
                        position (zero for the top, N to put it after the Nth other
                        widget). Note that this only has effect once, when the
                        widget is created.
                    <dt><code><strong>className</strong>: string</code></dt>
                    <dd>Add an extra CSS class name to the wrapper element
                        created for the widget.
                    </dd>
                </dl>
                Note that the widget node will become a descendant of nodes with
                CodeMirror-specific CSS classes, and those classes might in some
                cases affect it. This method returns an object that represents
                the widget placement. It'll have a <code>line</code> property
                pointing at the line handle that it is associated with, and the following methods:
                <dl>
                    <dt id="widget_clear"><code><strong>clear</strong>()</code></dt>
                    <dd>Removes the widget.</dd>
                    <dt id="widget_changed"><code><strong>changed</strong>()</code></dt>
                    <dd>Call
                        this if you made some change to the widget's DOM node that
                        might affect its height. It'll force CodeMirror to update
                        the height of the line that contains the widget.
                    </dd>
                </dl>
            </dd>
        </dl>

        <h3 id="api_sizing">Sizing, scrolling and positioning methods</h3>

        <dl>
            <dt id="setSize"><code><strong>cm.setSize</strong>(width: number|string, height: number|string)</code></dt>
            <dd>Programmatically set the size of the editor (overriding the
                applicable <a href="#css-resize">CSS
                    rules</a>). <code>width</code> and <code>height</code>
                can be either numbers (interpreted as pixels) or CSS units
                (<code>"100%"</code>, for example). You can
                pass <code>null</code> for either of them to indicate that that
                dimension should not be changed.
            </dd>

            <dt id="scrollTo"><code><strong>cm.scrollTo</strong>(x: number, y: number)</code></dt>
            <dd>Scroll the editor to a given (pixel) position. Both
                arguments may be left as <code>null</code>
                or <code>undefined</code> to have no effect.
            </dd>
            <dt id="getScrollInfo"><code><strong>cm.getScrollInfo</strong>() → {left, top, width, height, clientWidth,
                clientHeight}</code></dt>
            <dd>Get an <code>{left, top, width, height, clientWidth,
                clientHeight}</code> object that represents the current scroll
                position, the size of the scrollable area, and the size of the
                visible area (minus scrollbars).
            </dd>
            <dt id="scrollIntoView"><code><strong>cm.scrollIntoView</strong>(what: {line, ch}|{left, top, right,
                bottom}|{from, to}|null, ?margin: number)</code></dt>
            <dd>Scrolls the given position into view. <code>what</code> may
                be <code>null</code> to scroll the cursor into view,
                a <code>{line, ch}</code> position to scroll a character into
                view, a <code>{left, top, right, bottom}</code> pixel range (in
                editor-local coordinates), or a range <code>{from, to}</code>
                containing either two character positions or two pixel squares.
                The <code>margin</code> parameter is optional. When given, it
                indicates the amount of vertical pixels around the given area
                that should be made visible as well.
            </dd>

            <dt id="cursorCoords"><code><strong>cm.cursorCoords</strong>(where: boolean|{line, ch}, mode: string) →
                {left, top, bottom}</code></dt>
            <dd>Returns an <code>{left, top, bottom}</code> object
                containing the coordinates of the cursor position.
                If <code>mode</code> is <code>"local"</code>, they will be
                relative to the top-left corner of the editable document. If it
                is <code>"page"</code> or not given, they are relative to the
                top-left corner of the page. If <code>mode</code>
                is <code>"window"</code>, the coordinates are relative to the
                top-left corner of the currently visible (scrolled)
                window. <code>where</code> can be a boolean indicating whether
                you want the start (<code>true</code>) or the end
                (<code>false</code>) of the selection, or, if a <code>{line,
                    ch}</code> object is given, it specifies the precise position at
                which you want to measure.
            </dd>
            <dt id="charCoords"><code><strong>cm.charCoords</strong>(pos: {line, ch}, ?mode: string) → {left, right,
                top, bottom}</code></dt>
            <dd>Returns the position and dimensions of an arbitrary
                character. <code>pos</code> should be a <code>{line, ch}</code>
                object. This differs from <code>cursorCoords</code> in that
                it'll give the size of the whole character, rather than just the
                position that the cursor would have when it would sit at that
                position.
            </dd>
            <dt id="coordsChar"><code><strong>cm.coordsChar</strong>(object: {left, top}, ?mode: string) → {line,
                ch}</code></dt>
            <dd>Given an <code>{left, top}</code> object (e.g. coordinates of a mouse event) returns
                the <code>{line, ch}</code> position that corresponds to it. The
                optional <code>mode</code> parameter determines relative to what
                the coordinates are interpreted. It may
                be <code>"window"</code>, <code>"page"</code> (the default),
                or <code>"local"</code>.
            </dd>
            <dt id="lineAtHeight"><code><strong>cm.lineAtHeight</strong>(height: number, ?mode: string) → number</code>
            </dt>
            <dd>Computes the line at the given pixel
                height. <code>mode</code> can be one of the same strings
                that <a href="#coordsChar"><code>coordsChar</code></a>
                accepts.
            </dd>
            <dt id="heightAtLine"><code><strong>cm.heightAtLine</strong>(line: integer|LineHandle, ?mode: string,
                ?includeWidgets: bool) → number</code></dt>
            <dd>Computes the height of the top of a line, in the coordinate
                system specified by <code>mode</code>
                (see <a href="#coordsChar"><code>coordsChar</code></a>), which
                defaults to <code>"page"</code>. When a line below the bottom of
                the document is specified, the returned value is the bottom of
                the last line in the document. By default, the position of the
                actual text is returned. If `includeWidgets` is true and the
                line has line widgets, the position above the first line widget
                is returned.
            </dd>
            <dt id="defaultTextHeight"><code><strong>cm.defaultTextHeight</strong>() → number</code></dt>
            <dd>Returns the line height of the default font for the editor.</dd>
            <dt id="defaultCharWidth"><code><strong>cm.defaultCharWidth</strong>() → number</code></dt>
            <dd>Returns the pixel width of an 'x' in the default font for
                the editor. (Note that for non-monospace fonts, this is mostly
                useless, and even for monospace fonts, non-ascii characters
                might have a different width).
            </dd>

            <dt id="getViewport"><code><strong>cm.getViewport</strong>() → {from: number, to: number}</code></dt>
            <dd>Returns a <code>{from, to}</code> object indicating the
                start (inclusive) and end (exclusive) of the currently rendered
                part of the document. In big documents, when most content is
                scrolled out of view, CodeMirror will only render the visible
                part, and a margin around it. See also
                the <a href="#event_viewportChange"><code>viewportChange</code></a>
                event.
            </dd>

            <dt id="refresh"><code><strong>cm.refresh</strong>()</code></dt>
            <dd>If your code does something to change the size of the editor
                element (window resizes are already listened for), or unhides
                it, you should probably follow up by calling this method to
                ensure CodeMirror is still looking as intended. See also
                the <a href="#addon_autorefresh">autorefresh addon</a>.
            </dd>
        </dl>

        <h3 id="api_mode">Mode, state, and token-related methods</h3>

        <p>When writing language-aware functionality, it can often be
            useful to hook into the knowledge that the CodeMirror language
            mode has. See <a href="#modeapi">the section on modes</a> for a
            more detailed description of how these work.</p>

        <dl>
            <dt id="getMode"><code><strong>doc.getMode</strong>() → object</code></dt>
            <dd>Gets the (outer) mode object for the editor. Note that this
                is distinct from <code>getOption("mode")</code>, which gives you
                the mode specification, rather than the resolved, instantiated
                <a href="#defineMode">mode object</a>.
            </dd>

            <dt id="getModeAt"><code><strong>cm.getModeAt</strong>(pos: {line, ch}) → object</code></dt>
            <dd>Gets the inner mode at a given position. This will return
                the same as <a href="#getMode"><code>getMode</code></a> for
                simple modes, but will return an inner mode for nesting modes
                (such as <code>htmlmixed</code>).
            </dd>

            <dt id="getTokenAt"><code><strong>cm.getTokenAt</strong>(pos: {line, ch}, ?precise: boolean) → object</code>
            </dt>
            <dd>Retrieves information about the token the current mode found
                before the given position (a <code>{line, ch}</code> object). The
                returned object has the following properties:
                <dl>
                    <dt><code><strong>start</strong></code></dt>
                    <dd>The character (on the given line) at which the token starts.</dd>
                    <dt><code><strong>end</strong></code></dt>
                    <dd>The character at which the token ends.</dd>
                    <dt><code><strong>string</strong></code></dt>
                    <dd>The token's string.</dd>
                    <dt><code><strong>type</strong></code></dt>
                    <dd>The token type the mode assigned
                        to the token, such as <code>"keyword"</code>
                        or <code>"comment"</code> (may also be null).
                    </dd>
                    <dt><code><strong>state</strong></code></dt>
                    <dd>The mode's state at the end of this token.</dd>
                </dl>
                If <code>precise</code> is true, the token will be guaranteed to be accurate based on recent edits. If
                false or
                not specified, the token will use cached state information, which will be faster but might not be
                accurate if
                edits were recently made and highlighting has not yet completed.
            </dd>

            <dt id="getLineTokens"><code><strong>cm.getLineTokens</strong>(line: integer, ?precise: boolean) → array&lt;{start,
                end, string, type, state}&gt;</code></dt>
            <dd>This is similar
                to <a href="#getTokenAt"><code>getTokenAt</code></a>, but
                collects all tokens for a given line into an array. It is much
                cheaper than repeatedly calling <code>getTokenAt</code>, which
                re-parses the part of the line before the token for every call.
            </dd>

            <dt id="getTokenTypeAt"><code><strong>cm.getTokenTypeAt</strong>(pos: {line, ch}) → string</code></dt>
            <dd>This is a (much) cheaper version
                of <a href="#getTokenAt"><code>getTokenAt</code></a> useful for
                when you just need the type of the token at a given position,
                and no other information. Will return <code>null</code> for
                unstyled tokens, and a string, potentially containing multiple
                space-separated style names, otherwise.
            </dd>

            <dt id="getHelpers"><code><strong>cm.getHelpers</strong>(pos: {line, ch}, type: string) → array&lt;helper&gt;</code>
            </dt>
            <dd>Fetch the set of applicable helper values for the given
                position. Helpers provide a way to look up functionality
                appropriate for a mode. The <code>type</code> argument provides
                the helper namespace (see
                <a href="#registerHelper"><code>registerHelper</code></a>), in
                which the values will be looked up. When the mode itself has a
                property that corresponds to the <code>type</code>, that
                directly determines the keys that are used to look up the helper
                values (it may be either a single string, or an array of
                strings). Failing that, the mode's <code>helperType</code>
                property and finally the mode's name are used.
            </dd>
            <dd>For example, the JavaScript mode has a
                property <code>fold</code> containing <code>"brace"</code>. When
                the <code>brace-fold</code> addon is loaded, that defines a
                helper named <code>brace</code> in the <code>fold</code>
                namespace. This is then used by
                the <a href="#addon_foldcode"><code>foldcode</code></a> addon to
                figure out that it can use that folding function to fold
                JavaScript code.
            </dd>
            <dd>When any <a href="#registerGlobalHelper">'global'</a>
                helpers are defined for the given namespace, their predicates
                are called on the current mode and editor, and all those that
                declare they are applicable will also be added to the array that
                is returned.
            </dd>

            <dt id="getHelper"><code><strong>cm.getHelper</strong>(pos: {line, ch}, type: string) → helper</code></dt>
            <dd>Returns the first applicable helper value.
                See <a href="#getHelpers"><code>getHelpers</code></a>.
            </dd>

            <dt id="getStateAfter"><code><strong>cm.getStateAfter</strong>(?line: integer, ?precise: boolean) →
                object</code></dt>
            <dd>Returns the mode's parser state, if any, at the end of the
                given line number. If no line number is given, the state at the
                end of the document is returned. This can be useful for storing
                parsing errors in the state, or getting other kinds of
                contextual information for a line. <code>precise</code> is defined
                as in <code>getTokenAt()</code>.
            </dd>
        </dl>

        <h3 id="api_misc">Miscellaneous methods</h3>

        <dl>
            <dt id="operation"><code><strong>cm.operation</strong>(func: () → any) → any</code></dt>
            <dd>CodeMirror internally buffers changes and only updates its
                DOM structure after it has finished performing some operation.
                If you need to perform a lot of operations on a CodeMirror
                instance, you can call this method with a function argument. It
                will call the function, buffering up all changes, and only doing
                the expensive update after the function returns. This can be a
                lot faster. The return value from this method will be the return
                value of your function.
            </dd>

            <dt id="startOperation"><code><strong>cm.startOperation</strong>()</code></dt>
            <dt id="endOperation"><code><strong>cm.endOperation</strong>()</code></dt>
            <dd>In normal circumstances, use the above <code>operation</code>
                method. But if you want to buffer operations happening asynchronously,
                or that can't all be wrapped in a callback function, you can
                call <code>startOperation</code> to tell CodeMirror to start
                buffering changes, and <code>endOperation</code> to actually
                render all the updates. <em>Be careful:</em> if you use this
                API and forget to call <code>endOperation</code>, the editor will
                just never update.
            </dd>

            <dt id="indentLine"><code><strong>cm.indentLine</strong>(line: integer, ?dir: string|integer)</code></dt>
            <dd>Adjust the indentation of the given line. The second
                argument (which defaults to <code>"smart"</code>) may be one of:
                <dl>
                    <dt><code><strong>"prev"</strong></code></dt>
                    <dd>Base indentation on the indentation of the previous line.</dd>
                    <dt><code><strong>"smart"</strong></code></dt>
                    <dd>Use the mode's smart indentation if available, behave
                        like <code>"prev"</code> otherwise.
                    </dd>
                    <dt><code><strong>"add"</strong></code></dt>
                    <dd>Increase the indentation of the line by
                        one <a href="#option_indentUnit">indent unit</a>.
                    </dd>
                    <dt><code><strong>"subtract"</strong></code></dt>
                    <dd>Reduce the indentation of the line.</dd>
                    <dt><code><strong>&lt;integer></strong></code></dt>
                    <dd>Add (positive number) or reduce (negative number) the
                        indentation by the given amount of spaces.
                    </dd>
                </dl>
            </dd>

            <dt id="toggleOverwrite"><code><strong>cm.toggleOverwrite</strong>(?value: boolean)</code></dt>
            <dd>Switches between overwrite and normal insert mode (when not
                given an argument), or sets the overwrite mode to a specific
                state (when given an argument).
            </dd>

            <dt id="isReadOnly"><code><strong>cm.isReadOnly</strong>() → boolean</code></dt>
            <dd>Tells you whether the editor's content can be edited by the
                user.
            </dd>

            <dt id="lineSeparator"><code><strong>doc.lineSeparator</strong>()</code></dt>
            <dd>Returns the preferred line separator string for this
                document, as per the <a href="#option_lineSeparator">option</a>
                by the same name. When that option is <code>null</code>, the
                string <code>"\n"</code> is returned.
            </dd>

            <dt id="execCommand"><code><strong>cm.execCommand</strong>(name: string)</code></dt>
            <dd>Runs the <a href="#commands">command</a> with the given name on the editor.</dd>

            <dt id="posFromIndex"><code><strong>doc.posFromIndex</strong>(index: integer) → {line, ch}</code></dt>
            <dd>Calculates and returns a <code>{line, ch}</code> object for a
                zero-based <code>index</code> who's value is relative to the start of the
                editor's text. If the <code>index</code> is out of range of the text then
                the returned object is clipped to start or end of the text
                respectively.
            </dd>
            <dt id="indexFromPos"><code><strong>doc.indexFromPos</strong>(object: {line, ch}) → integer</code></dt>
            <dd>The reverse of <a href="#posFromIndex"><code>posFromIndex</code></a>.</dd>

            <dt id="focus"><code><strong>cm.focus</strong>()</code></dt>
            <dd>Give the editor focus.</dd>

            <dt id="phrase"><code><strong>cm.phrase</strong>(text: string) → string</code></dt>
            <dd>Allow the given string to be translated with
                the <a href="#option_phrases"><code>phrases</code>
                    option</a>.
            </dd>

            <dt id="getInputField"><code><strong>cm.getInputField</strong>() → Element</code></dt>
            <dd>Returns the input field for the editor. Will be a textarea
                or an editable div, depending on the value of
                the <a href="#option_inputStyle"><code>inputStyle</code></a>
                option.
            </dd>
            <dt id="getWrapperElement"><code><strong>cm.getWrapperElement</strong>() → Element</code></dt>
            <dd>Returns the DOM node that represents the editor, and
                controls its size. Remove this from your tree to delete an
                editor instance.
            </dd>
            <dt id="getScrollerElement"><code><strong>cm.getScrollerElement</strong>() → Element</code></dt>
            <dd>Returns the DOM node that is responsible for the scrolling
                of the editor.
            </dd>
            <dt id="getGutterElement"><code><strong>cm.getGutterElement</strong>() → Element</code></dt>
            <dd>Fetches the DOM node that contains the editor gutters.</dd>
        </dl>

        <h3 id="api_static">Static properties</h3>
        <p>The <code>CodeMirror</code> object itself provides
            several useful properties.</p>

        <dl>
            <dt id="version"><code><strong>CodeMirror.version</strong>: string</code></dt>
            <dd>It contains a string that indicates the version of the
                library. This is a triple of
                integers <code>"major.minor.patch"</code>,
                where <code>patch</code> is zero for releases, and something
                else (usually one) for dev snapshots.
            </dd>

            <dt id="fromTextArea"><code><strong>CodeMirror.fromTextArea</strong>(textArea: TextAreaElement, ?config:
                object)</code></dt>
            <dd>This method provides another way to initialize an editor. It
                takes a textarea DOM node as first argument and an optional
                configuration object as second. It will replace the textarea
                with a CodeMirror instance, and wire up the form of that
                textarea (if any) to make sure the editor contents are put into
                the textarea when the form is submitted. The text in the
                textarea will provide the content for the editor. A CodeMirror
                instance created this way has three additional methods:
                <dl>
                    <dt id="save"><code><strong>cm.save</strong>()</code></dt>
                    <dd>Copy the content of the editor into the textarea.</dd>

                    <dt id="toTextArea"><code><strong>cm.toTextArea</strong>()</code></dt>
                    <dd>Remove the editor, and restore the original textarea (with
                        the editor's current content). If you dynamically create and
                        destroy editors made with `fromTextArea`, without destroying
                        the form they are part of, you should make sure to call
                        `toTextArea` to remove the editor, or its `"submit"` handler
                        on the form will cause a memory leak.
                    </dd>

                    <dt id="getTextArea"><code><strong>cm.getTextArea</strong>() → TextAreaElement</code></dt>
                    <dd>Returns the textarea that the instance was based on.</dd>
                </dl>
            </dd>

            <dt id="defaults"><code><strong>CodeMirror.defaults</strong>: object</code></dt>
            <dd>An object containing default values for
                all <a href="#config">options</a>. You can assign to its
                properties to modify defaults (though this won't affect editors
                that have already been created).
            </dd>

            <dt id="defineExtension"><code><strong>CodeMirror.defineExtension</strong>(name: string, value: any)</code>
            </dt>
            <dd>If you want to define extra methods in terms of the
                CodeMirror API, it is possible to
                use <code>defineExtension</code>. This will cause the given
                value (usually a method) to be added to all CodeMirror instances
                created from then on.
            </dd>

            <dt id="defineDocExtension"><code><strong>CodeMirror.defineDocExtension</strong>(name: string, value:
                any)</code></dt>
            <dd>Like <a href="#defineExtension"><code>defineExtension</code></a>,
                but the method will be added to the interface
                for <a href="#Doc"><code>Doc</code></a> objects instead.
            </dd>

            <dt id="defineOption"><code><strong>CodeMirror.defineOption</strong>(name: string,
                default: any, updateFunc: function)</code></dt>
            <dd>Similarly, <code>defineOption</code> can be used to define new options for
                CodeMirror. The <code>updateFunc</code> will be called with the
                editor instance and the new value when an editor is initialized,
                and whenever the option is modified
                through <a href="#setOption"><code>setOption</code></a>.
            </dd>

            <dt id="defineInitHook"><code><strong>CodeMirror.defineInitHook</strong>(func: function)</code></dt>
            <dd>If your extension just needs to run some
                code whenever a CodeMirror instance is initialized,
                use <code>CodeMirror.defineInitHook</code>. Give it a function as
                its only argument, and from then on, that function will be called
                (with the instance as argument) whenever a new CodeMirror instance
                is initialized.
            </dd>

            <dt id="registerHelper"><code><strong>CodeMirror.registerHelper</strong>(type: string, name: string,
                value: helper)</code></dt>
            <dd>Registers a helper value with the given <code>name</code> in
                the given namespace (<code>type</code>). This is used to define
                functionality that may be looked up by mode. Will create (if it
                doesn't already exist) a property on the <code>CodeMirror</code>
                object for the given <code>type</code>, pointing to an object
                that maps names to values. I.e. after
                doing <code>CodeMirror.registerHelper("hint", "foo",
                    myFoo)</code>, the value <code>CodeMirror.hint.foo</code> will
                point to <code>myFoo</code>.
            </dd>

            <dt id="registerGlobalHelper"><code><strong>CodeMirror.registerGlobalHelper</strong>(type: string,
                name: string, predicate: fn(mode, CodeMirror), value: helper)</code></dt>
            <dd>Acts
                like <a href="#registerHelper"><code>registerHelper</code></a>,
                but also registers this helper as 'global', meaning that it will
                be included by <a href="#getHelpers"><code>getHelpers</code></a>
                whenever the given <code>predicate</code> returns true when
                called with the local mode and editor.
            </dd>

            <dt id="Pos"><code><strong>CodeMirror.Pos</strong>(line: integer, ?ch: integer, ?sticky: string)</code></dt>
            <dd>A constructor for the objects that are used to represent
                positions in editor documents. <code>sticky</code> defaults to
                null, but can be set to <code>"before"</code>
                or <code>"after"</code> to make the position explicitly
                associate with the character before or after it.
            </dd>

            <dt id="changeEnd"><code><strong>CodeMirror.changeEnd</strong>(change: object) → {line, ch}</code></dt>
            <dd>Utility function that computes an end position from a change
                (an object with <code>from</code>, <code>to</code>,
                and <code>text</code> properties, as passed to
                various <a href="#event_change">event handlers</a>). The
                returned position will be the end of the changed
                range, <em>after</em> the change is applied.
            </dd>

            <dt id="countColumn"><code><strong>CodeMirror.countColumn</strong>(line: string, index: number, tabSize:
                number) → number</code></dt>
            <dd>Find the column position at a given string index using a given tabsize.</dd>
        </dl>
    </section>

    <section id=addons>
        <h2 id="addons">Addons</h2>

        <p>The <code>addon</code> directory in the distribution contains a
            number of reusable components that implement extra editor
            functionality (on top of extension functions
            like <a href="#defineOption"><code>defineOption</code></a>, <a
                    href="#defineExtension"><code>defineExtension</code></a>,
            and <a href="#registerHelper"><code>registerHelper</code></a>). In
            brief, they are:</p>

        <dl>
            <dt id="addon_dialog"><a href="../addon/dialog/dialog.js"><code>dialog/dialog.js</code></a></dt>
            <dd>Provides a very simple way to query users for text input.
                Adds the <strong><code>openDialog(template, callback, options) →
                    closeFunction</code></strong> method to CodeMirror instances,
                which can be called with an HTML fragment or a detached DOM
                node that provides the prompt (should include an <code>input</code>
                or <code>button</code> tag), and a callback function that is called
                when the user presses enter. It returns a function <code>closeFunction</code>
                which, if called, will close the dialog immediately.
                <strong><code>openDialog</code></strong> takes the following options:
                <dl>
                    <dt><code><strong>closeOnEnter</strong>: bool</code></dt>
                    <dd>If true, the dialog will be closed when the user presses
                        enter in the input. Defaults to <code>true</code>.
                    </dd>
                    <dt><code><strong>closeOnBlur</strong>: bool</code></dt>
                    <dd>Determines whether the dialog is closed when it loses focus. Defaults to <code>true</code>.</dd>
                    <dt><code><strong>onKeyDown</strong>: fn(event: KeyboardEvent, value: string, close: fn()) →
                        bool</code></dt>
                    <dd>An event handler that will be called whenever <code>keydown</code> fires in the
                        dialog's input. If your callback returns <code>true</code>,
                        the dialog will not do any further processing of the event.
                    </dd>
                    <dt><code><strong>onKeyUp</strong>: fn(event: KeyboardEvent, value: string, close: fn()) →
                        bool</code></dt>
                    <dd>Same as <code>onKeyDown</code> but for the
                        <code>keyup</code> event.
                    </dd>
                    <dt><code><strong>onInput</strong>: fn(event: InputEvent, value: string, close: fn()) → bool</code>
                    </dt>
                    <dd>Same as <code>onKeyDown</code> but for the
                        <code>input</code> event.
                    </dd>
                    <dt><code><strong>onClose</strong>: fn(instance)</code>:</dt>
                    <dd>A callback that will be called after the dialog has been closed and
                        removed from the DOM. No return value.
                    </dd>
                </dl>

                <p>Also adds an <strong><code>openNotification(template, options) →
                    closeFunction</code></strong> function that simply shows an HTML
                    fragment as a notification at the top of the editor. It takes a
                    single option: <code>duration</code>, the amount of time after
                    which the notification will be automatically closed. If <code>
                        duration</code> is zero, the dialog will not be closed automatically.</p>

                <p>Depends on <code>addon/dialog/dialog.css</code>.</p></dd>

            <dt id="addon_searchcursor"><a
                    href="../addon/search/searchcursor.js"><code>search/searchcursor.js</code></a></dt>
            <dd>Adds the <code>getSearchCursor(query, start, options) →
                cursor</code> method to CodeMirror instances, which can be used
                to implement search/replace functionality. <code>query</code>
                can be a regular expression or a string. <code>start</code>
                provides the starting position of the search. It can be
                a <code>{line, ch}</code> object, or can be left off to default
                to the start of the document. <code>options</code> is an
                optional object, which can contain the property `caseFold:
                false` to disable case folding when matching a string, or the
                property `multiline: disable` to disable multi-line matching for
                regular expressions (which may help performance). A search
                cursor has the following methods:
                <dl>
                    <dt><code><strong>findNext</strong>() → boolean</code></dt>
                    <dt><code><strong>findPrevious</strong>() → boolean</code></dt>
                    <dd>Search forward or backward from the current position.
                        The return value indicates whether a match was found. If
                        matching a regular expression, the return value will be the
                        array returned by the <code>match</code> method, in case you
                        want to extract matched groups.
                    </dd>
                    <dt><code><strong>from</strong>() → {line, ch}</code></dt>
                    <dt><code><strong>to</strong>() → {line, ch}</code></dt>
                    <dd>These are only valid when the last call
                        to <code>findNext</code> or <code>findPrevious</code> did
                        not return false. They will return <code>{line, ch}</code>
                        objects pointing at the start and end of the match.
                    </dd>
                    <dt><code><strong>replace</strong>(text: string, ?origin: string)</code></dt>
                    <dd>Replaces the currently found match with the given text
                        and adjusts the cursor position to reflect the
                        replacement.
                    </dd>
                </dl>
            </dd>

            <dt id="addon_search"><a href="../addon/search/search.js"><code>search/search.js</code></a></dt>
            <dd>Implements the search commands. CodeMirror has keys bound to
                these by default, but will not do anything with them unless an
                implementation is provided. Depends
                on <code>searchcursor.js</code>, and will make use
                of <a href="#addon_dialog"><code>openDialog</code></a> when
                available to make prompting for search queries less ugly.
            </dd>

            <dt id="addon_jump-to-line"><a
                    href="../addon/search/jump-to-line.js"><code>search/jump-to-line.js</code></a></dt>
            <dd>Implements a <code>jumpToLine</code> command and binding <code>Alt-G</code> to it.
                Accepts <code>linenumber</code>, <code>+/-linenumber</code>, <code>line:char</code>,
                <code>scroll%</code> and <code>:linenumber</code> formats.
                This will make use of <a href="#addon_dialog"><code>openDialog</code></a>
                when available to make prompting for line number neater.
            </dd>

            <dt id="addon_matchesonscrollbar"><a href="../addon/search/matchesonscrollbar.js"><code>search/matchesonscrollbar.js</code></a>
            </dt>
            <dd>Adds a <code>showMatchesOnScrollbar</code> method to editor
                instances, which should be given a query (string or regular
                expression), optionally a case-fold flag (only applicable for
                strings), and optionally a class name (defaults
                to <code>CodeMirror-search-match</code>) as arguments. When
                called, matches of the given query will be displayed on the
                editor's vertical scrollbar. The method returns an object with
                a <code>clear</code> method that can be called to remove the
                matches. Depends on
                the <a href="#addon_annotatescrollbar"><code>annotatescrollbar</code></a>
                addon, and
                the <a href="../addon/search/matchesonscrollbar.css"><code>matchesonscrollbar.css</code></a>
                file provides a default (transparent yellowish) definition of
                the CSS class applied to the matches. Note that the matches are
                only perfectly aligned if your scrollbar does not have buttons
                at the top and bottom. You can use
                the <a href="#addon_simplescrollbars"><code>simplescrollbar</code></a>
                addon to make sure of this. If this addon is loaded,
                the <a href="#addon_search"><code>search</code></a> addon will
                automatically use it.
            </dd>

            <dt id="addon_matchbrackets"><a href="../addon/edit/matchbrackets.js"><code>edit/matchbrackets.js</code></a>
            </dt>
            <dd>Defines an option <code>matchBrackets</code> which, when set
                to true or an options object, causes matching brackets to be
                highlighted whenever the cursor is next to them. It also adds a
                method <code>matchBrackets</code> that forces this to happen
                once, and a method <code>findMatchingBracket</code> that can be
                used to run the bracket-finding algorithm that this uses
                internally. It takes a start position and an optional config
                object. By default, it will find the match to a matchable
                character either before or after the cursor (preferring the one
                before), but you can control its behavior with these options:
                <dl>
                    <dt><strong><code>afterCursor</code></strong></dt>
                    <dd>Only use the character after the start position, never the one before it.</dd>
                    <dt><strong><code>strict</code></strong></dt>
                    <dd>Causes only matches where both brackets are at the same side of the start position to be
                        considered.
                    </dd>
                    <dt><strong><code>maxScanLines</code></strong></dt>
                    <dd>Stop after scanning this amount of lines without a successful match. Defaults to 1000.</dd>
                    <dt><strong><code>maxScanLineLength</code></strong></dt>
                    <dd>Ignore lines longer than this. Defaults to 10000.</dd>
                    <dt><strong><code>maxHighlightLineLength</code></strong></dt>
                    <dd>Don't highlight a bracket in a line longer than this. Defaults to 1000.</dd>
                </dl>
            </dd>

            <dt id="addon_closebrackets"><a href="../addon/edit/closebrackets.js"><code>edit/closebrackets.js</code></a>
            </dt>
            <dd>Defines an option <code>autoCloseBrackets</code> that will
                auto-close brackets and quotes when typed. By default, it'll
                auto-close <code>()[]{}''""</code>, but you can pass it a string
                similar to that (containing pairs of matching characters), or an
                object with <code>pairs</code> and
                optionally <code>explode</code> properties to customize
                it. <code>explode</code> should be a similar string that gives
                the pairs of characters that, when enter is pressed between
                them, should have the second character also moved to its own
                line. By default, if the active mode has
                a <code>closeBrackets</code> property, that overrides the
                configuration given in the option. But you can add
                an <code>override</code> property with a truthy value to
                override mode-specific
                configuration. <a href="../demo/closebrackets.html">Demo
                    here</a>.
            </dd>

            <dt id="addon_matchtags"><a href="../addon/edit/matchtags.js"><code>edit/matchtags.js</code></a></dt>
            <dd>Defines an option <code>matchTags</code> that, when enabled,
                will cause the tags around the cursor to be highlighted (using
                the <code>CodeMirror-matchingtag</code> class). Also
                defines
                a <a href="#commands">command</a> <code>toMatchingTag</code>,
                which you can bind a key to in order to jump to the tag matching
                the one under the cursor. Depends on
                the <code>addon/fold/xml-fold.js</code>
                addon. <a href="../demo/matchtags.html">Demo here.</a></dd>

            <dt id="addon_trailingspace"><a href="../addon/edit/trailingspace.js"><code>edit/trailingspace.js</code></a>
            </dt>
            <dd>Adds an option <code>showTrailingSpace</code> which, when
                enabled, adds the CSS class <code>cm-trailingspace</code> to
                stretches of whitespace at the end of lines.
                The <a href="../demo/trailingspace.html">demo</a> has a nice
                squiggly underline style for this class.
            </dd>

            <dt id="addon_closetag"><a href="../addon/edit/closetag.js"><code>edit/closetag.js</code></a></dt>
            <dd>Defines an <code>autoCloseTags</code> option that will
                auto-close XML tags when '<code>&gt;</code>' or '<code>/</code>'
                is typed, and
                a <code>closeTag</code> <a href="#commands">command</a> that
                closes the nearest open tag. Depends on
                the <code>fold/xml-fold.js</code> addon. See
                the <a href="../demo/closetag.html">demo</a>.
            </dd>

            <dt id="addon_continuelist"><a href="../addon/edit/continuelist.js"><code>edit/continuelist.js</code></a>
            </dt>
            <dd>Markdown specific. Defines
                a <code>"newlineAndIndentContinueMarkdownList"</code> <a href="#commands">command</a>
                that can be bound to <code>enter</code> to automatically
                insert the leading characters for continuing a list. See
                the <a href="../mode/markdown/index.html">Markdown mode
                    demo</a>.
            </dd>

            <dt id="addon_comment"><a href="../addon/comment/comment.js"><code>comment/comment.js</code></a></dt>
            <dd>Addon for commenting and uncommenting code. Adds four
                methods to CodeMirror instances:
                <dl>
                    <dt id="toggleComment"><code><strong>toggleComment</strong>(?options: object)</code></dt>
                    <dd>Tries to uncomment the current selection, and if that
                        fails, line-comments it.
                    </dd>
                    <dt id="lineComment"><code><strong>lineComment</strong>(from: {line, ch}, to: {line, ch}, ?options:
                        object)</code></dt>
                    <dd>Set the lines in the given range to be line comments. Will
                        fall back to <code>blockComment</code> when no line comment
                        style is defined for the mode.
                    </dd>
                    <dt id="blockComment"><code><strong>blockComment</strong>(from: {line, ch}, to: {line, ch},
                        ?options: object)</code></dt>
                    <dd>Wrap the code in the given range in a block comment. Will
                        fall back to <code>lineComment</code> when no block comment
                        style is defined for the mode.
                    </dd>
                    <dt id="uncomment"><code><strong>uncomment</strong>(from: {line, ch}, to: {line, ch}, ?options:
                        object) → boolean</code></dt>
                    <dd>Try to uncomment the given range.
                        Returns <code>true</code> if a comment range was found and
                        removed, <code>false</code> otherwise.
                    </dd>
                </dl>
                The <code>options</code> object accepted by these methods may
                have the following properties:
                <dl>
                    <dt><code>blockCommentStart, blockCommentEnd, blockCommentLead, lineComment: string</code></dt>
                    <dd>Override the <a href="#mode_comment">comment string
                        properties</a> of the mode with custom comment strings.
                    </dd>
                    <dt><code><strong>padding</strong>: string</code></dt>
                    <dd>A string that will be inserted after opening and leading
                        markers, and before closing comment markers. Defaults to a
                        single space.
                    </dd>
                    <dt><code><strong>commentBlankLines</strong>: boolean</code></dt>
                    <dd>Whether, when adding line comments, to also comment lines
                        that contain only whitespace.
                    </dd>
                    <dt><code><strong>indent</strong>: boolean</code></dt>
                    <dd>When adding line comments and this is turned on, it will
                        align the comment block to the current indentation of the
                        first line of the block.
                    </dd>
                    <dt><code><strong>fullLines</strong>: boolean</code></dt>
                    <dd>When block commenting, this controls whether the whole
                        lines are indented, or only the precise range that is given.
                        Defaults to <code>true</code>.
                    </dd>
                </dl>
                The addon also defines
                a <code>toggleComment</code> <a href="#commands">command</a>,
                which is a shorthand command for calling
                <code>toggleComment</code> with no options.
            </dd>

            <dt id="addon_foldcode"><a href="../addon/fold/foldcode.js"><code>fold/foldcode.js</code></a></dt>
            <dd>Helps with code folding. Adds a <code>foldCode</code> method
                to editor instances, which will try to do a code fold starting
                at the given line, or unfold the fold that is already present.
                The method takes as first argument the position that should be
                folded (may be a line number or
                a <a href="#Pos"><code>Pos</code></a>), and as second optional
                argument either a range-finder function, or an options object,
                supporting the following properties:
                <dl>
                    <dt><code><strong>rangeFinder</strong>: fn(CodeMirror, Pos)</code></dt>
                    <dd id="helper_fold_auto">The function that is used to find
                        foldable ranges. If this is not directly passed, it will
                        default to <code>CodeMirror.fold.auto</code>, which
                        uses <a href="#getHelpers"><code>getHelpers</code></a> with
                        a <code>"fold"</code> type to find folding functions
                        appropriate for the local mode. There are files in
                        the <a href="../addon/fold/"><code>addon/fold/</code></a>
                        directory providing <code>CodeMirror.fold.brace</code>, which
                        finds blocks in brace languages (JavaScript, C, Java,
                        etc), <code>CodeMirror.fold.indent</code>, for languages where
                        indentation determines block structure (Python, Haskell),
                        and <code>CodeMirror.fold.xml</code>, for XML-style languages,
                        and <code>CodeMirror.fold.comment</code>, for folding comment
                        blocks.
                    </dd>
                    <dt><code><strong>widget</strong>: string | Element | fn(from: Pos, to: Pos) → string|Element</code>
                    </dt>
                    <dd>The widget to show for folded ranges. Can be either a
                        string, in which case it'll become a span with
                        class <code>CodeMirror-foldmarker</code>, or a DOM node.
                        To dynamically generate the widget, this can be a function
                        that returns a string or DOM node, which will then render
                        as described. The function will be invoked with parameters
                        identifying the range to be folded.
                    </dd>
                    <dt><code><strong>scanUp</strong>: boolean</code></dt>
                    <dd>When true (default is false), the addon will try to find
                        foldable ranges on the lines above the current one if there
                        isn't an eligible one on the given line.
                    </dd>
                    <dt><code><strong>minFoldSize</strong>: integer</code></dt>
                    <dd>The minimum amount of lines that a fold should span to be
                        accepted. Defaults to 0, which also allows single-line
                        folds.
                    </dd>
                </dl>
                See <a href="../demo/folding.html">the demo</a> for an
                example.
            </dd>

            <dt id="addon_foldgutter"><a href="../addon/fold/foldgutter.js"><code>fold/foldgutter.js</code></a></dt>
            <dd>Provides an option <code>foldGutter</code>, which can be
                used to create a gutter with markers indicating the blocks that
                can be folded. Create a gutter using
                the <a href="#option_gutters"><code>gutters</code></a> option,
                giving it the class <code>CodeMirror-foldgutter</code> or
                something else if you configure the addon to use a different
                class, and this addon will show markers next to folded and
                foldable blocks, and handle clicks in this gutter. Note that
                CSS styles should be applied to make the gutter, and the fold
                markers within it, visible. A default set of CSS styles are
                available in:
                <a href="../addon/fold/foldgutter.css">
                    <code>addon/fold/foldgutter.css</code>
                </a>.
                The option
                can be either set to <code>true</code>, or an object containing
                the following optional option fields:
                <dl>
                    <dt><code><strong>gutter</strong>: string</code></dt>
                    <dd>The CSS class of the gutter. Defaults
                        to <code>"CodeMirror-foldgutter"</code>. You will have to
                        style this yourself to give it a width (and possibly a
                        background). See the default gutter style rules above.
                    </dd>
                    <dt><code><strong>indicatorOpen</strong>: string | Element</code></dt>
                    <dd>A CSS class or DOM element to be used as the marker for
                        open, foldable blocks. Defaults
                        to <code>"CodeMirror-foldgutter-open"</code>.
                    </dd>
                    <dt><code><strong>indicatorFolded</strong>: string | Element</code></dt>
                    <dd>A CSS class or DOM element to be used as the marker for
                        folded blocks. Defaults to <code>"CodeMirror-foldgutter-folded"</code>.
                    </dd>
                    <dt><code><strong>rangeFinder</strong>: fn(CodeMirror, Pos)</code></dt>
                    <dd>The range-finder function to use when determining whether
                        something can be folded. When not
                        given, <a href="#helper_fold_auto"><code>CodeMirror.fold.auto</code></a>
                        will be used as default.
                    </dd>
                </dl>
                The <code>foldOptions</code> editor option can be set to an
                object to provide an editor-wide default configuration.
                Demo <a href="../demo/folding.html">here</a>.
            </dd>

            <dt id="addon_runmode"><a href="../addon/runmode/runmode.js"><code>runmode/runmode.js</code></a></dt>
            <dd>Can be used to run a CodeMirror mode over text without
                actually opening an editor instance.
                See <a href="../demo/runmode.html">the demo</a> for an example.
                There are alternate versions of the file available for
                running <a href="../addon/runmode/runmode-standalone.js">stand-alone</a>
                (without including all of CodeMirror) and
                for <a href="../addon/runmode/runmode.node.js">running under
                    node.js</a> (see <code>bin/source-highlight</code> for an example of using the latter).
            </dd>

            <dt id="addon_colorize"><a href="../addon/runmode/colorize.js"><code>runmode/colorize.js</code></a></dt>
            <dd>Provides a convenient way to syntax-highlight code snippets
                in a webpage. Depends on
                the <a href="#addon_runmode"><code>runmode</code></a> addon (or
                its standalone variant). Provides
                a <code>CodeMirror.colorize</code> function that can be called
                with an array (or other array-ish collection) of DOM nodes that
                represent the code snippets. By default, it'll get
                all <code>pre</code> tags. Will read the <code>data-lang</code>
                attribute of these nodes to figure out their language, and
                syntax-color their content using the relevant CodeMirror mode
                (you'll have to load the scripts for the relevant modes
                yourself). A second argument may be provided to give a default
                mode, used when no language attribute is found for a node. Used
                in this manual to highlight example code.
            </dd>

            <dt id="addon_overlay"><a href="../addon/mode/overlay.js"><code>mode/overlay.js</code></a></dt>
            <dd>Mode combinator that can be used to extend a mode with an
                'overlay' — a secondary mode is run over the stream, along with
                the base mode, and can color specific pieces of text without
                interfering with the base mode.
                Defines <code>CodeMirror.overlayMode</code>, which is used to
                create such a mode. See <a href="../demo/mustache.html">this
                    demo</a> for a detailed example.
            </dd>

            <dt id="addon_multiplex"><a href="../addon/mode/multiplex.js"><code>mode/multiplex.js</code></a></dt>
            <dd>Mode combinator that can be used to easily 'multiplex'
                between several modes.
                Defines <code>CodeMirror.multiplexingMode</code> which, when
                given as first argument a mode object, and as other arguments
                any number of <code>{open, close, mode [, delimStyle, innerStyle, parseDelimiters]}</code>
                objects, will return a mode object that starts parsing using the
                mode passed as first argument, but will switch to another mode
                as soon as it encounters a string that occurs in one of
                the <code>open</code> fields of the passed objects. When in a
                sub-mode, it will go back to the top mode again when
                the <code>close</code> string is encountered.
                Pass <code>"\n"</code> for <code>open</code> or <code>close</code>
                if you want to switch on a blank line.
                <ul>
                    <li>When <code>delimStyle</code> is specified, it will be the token
                        style returned for the delimiter tokens (as well as
                        <code>[delimStyle]-open</code> on the opening token and
                        <code>[delimStyle]-close</code> on the closing token).
                    </li>
                    <li>When <code>innerStyle</code> is specified, it will be the token
                        style added for each inner mode token.
                    </li>
                    <li>When <code>parseDelimiters</code> is true, the content of
                        the delimiters will also be passed to the inner mode.
                        (And <code>delimStyle</code> is ignored.)
                    </li>
                </ul>
                The outer
                mode will not see the content between the delimiters.
                See <a href="../demo/multiplex.html">this demo</a> for an
                example.
            </dd>

            <dt id="addon_show-hint"><a href="../addon/hint/show-hint.js"><code>hint/show-hint.js</code></a></dt>
            <dd>Provides a framework for showing autocompletion hints.
                Defines <code>editor.showHint</code>, which takes an optional
                options object, and pops up a widget that allows the user to
                select a completion. Finding hints is done with a hinting
                functions (the <code>hint</code> option), which is a function
                that take an editor instance and options object, and return
                a <code>{list, from, to}</code> object, where <code>list</code>
                is an array of strings or objects (the completions),
                and <code>from</code> and <code>to</code> give the start and end
                of the token that is being completed as <code>{line, ch}</code>
                objects. An optional <code>selectedHint</code> property (an
                integer) can be added to the completion object to control the
                initially selected hint.
            </dd>
            <dd>If no hinting function is given, the addon will
                use <code>CodeMirror.hint.auto</code>, which
                calls <a href="#getHelpers"><code>getHelpers</code></a> with
                the <code>"hint"</code> type to find applicable hinting
                functions, and tries them one by one. If that fails, it looks
                for a <code>"hintWords"</code> helper to fetch a list of
                completable words for the mode, and
                uses <code>CodeMirror.hint.fromList</code> to complete from
                those.
            </dd>
            <dd>When completions aren't simple strings, they should be
                objects with the following properties:
                <dl>
                    <dt><code><strong>text</strong>: string</code></dt>
                    <dd>The completion text. This is the only required
                        property.
                    </dd>
                    <dt><code><strong>displayText</strong>: string</code></dt>
                    <dd>The text that should be displayed in the menu.</dd>
                    <dt><code><strong>className</strong>: string</code></dt>
                    <dd>A CSS class name to apply to the completion's line in the
                        menu.
                    </dd>
                    <dt><code><strong>render</strong>: fn(Element, self, data)</code></dt>
                    <dd>A method used to create the DOM structure for showing the
                        completion by appending it to its first argument.
                    </dd>
                    <dt><code><strong>hint</strong>: fn(CodeMirror, self, data)</code></dt>
                    <dd>A method used to actually apply the completion, instead of
                        the default behavior.
                    </dd>
                    <dt><code><strong>from</strong>: {line, ch}</code></dt>
                    <dd>Optional <code>from</code> position that will be used by <code>pick()</code> instead
                        of the global one passed with the full list of completions.
                    </dd>
                    <dt><code><strong>to</strong>: {line, ch}</code></dt>
                    <dd>Optional <code>to</code> position that will be used by <code>pick()</code> instead
                        of the global one passed with the full list of completions.
                    </dd>
                </dl>
            </dd>

            <dd>The plugin understands the following options, which may be
                either passed directly in the argument to <code>showHint</code>,
                or provided by setting an <code>hintOptions</code> editor
                option to an object (the former takes precedence). The options
                object will also be passed along to the hinting function, which
                may understand additional options.
                <dl>
                    <dt><code><strong>hint</strong>: function</code></dt>
                    <dd>A hinting function, as specified above. It is possible to
                        set the <code>async</code> property on a hinting function to
                        true, in which case it will be called with
                        arguments <code>(cm, callback, ?options)</code>, and the
                        completion interface will only be popped up when the hinting
                        function calls the callback, passing it the object holding the
                        completions.
                        The hinting function can also return a promise, and the completion
                        interface will only be popped when the promise resolves.
                        By default, hinting only works when there is no
                        selection. You can give a hinting function
                        a <code>supportsSelection</code> property with a truthy value
                        to indicate that it supports selections.
                    </dd>
                    <dt><code><strong>completeSingle</strong>: boolean</code></dt>
                    <dd>Determines whether, when only a single completion is
                        available, it is completed without showing the dialog.
                        Defaults to true.
                    </dd>
                    <dt><code><strong>alignWithWord</strong>: boolean</code></dt>
                    <dd>Whether the pop-up should be horizontally aligned with the
                        start of the word (true, default), or with the cursor (false).
                    </dd>
                    <dt><code><strong>closeOnUnfocus</strong>: boolean</code></dt>
                    <dd>When enabled (which is the default), the pop-up will close
                        when the editor is unfocused.
                    </dd>
                    <dt><code><strong>customKeys</strong>: keymap</code></dt>
                    <dd>Allows you to provide a custom key map of keys to be active
                        when the pop-up is active. The handlers will be called with an
                        extra argument, a handle to the completion menu, which
                        has <code>moveFocus(n)</code>, <code>setFocus(n)</code>, <code>pick()</code>,
                        and <code>close()</code> methods (see the source for details),
                        that can be used to change the focused element, pick the
                        current element or close the menu. Additionally <code>menuSize()</code>
                        can give you access to the size of the current dropdown menu,
                        <code>length</code> give you the number of available completions, and
                        <code>data</code> give you full access to the completion returned by the
                        hinting function.
                    </dd>
                    <dt><code><strong>extraKeys</strong>: keymap</code></dt>
                    <dd>Like <code>customKeys</code> above, but the bindings will
                        be added to the set of default bindings, instead of replacing
                        them.
                    </dd>
                </dl>
                The following events will be fired on the completions object
                during completion:
                <dl>
                    <dt><code><strong>"shown"</strong> ()</code></dt>
                    <dd>Fired when the pop-up is shown.</dd>
                    <dt><code><strong>"select"</strong> (completion, Element)</code></dt>
                    <dd>Fired when a completion is selected. Passed the completion
                        value (string or object) and the DOM node that represents it
                        in the menu.
                    </dd>
                    <dt><code><strong>"pick"</strong> (completion)</code></dt>
                    <dd>Fired when a completion is picked. Passed the completion value
                        (string or object).
                    </dd>
                    <dt><code><strong>"close"</strong> ()</code></dt>
                    <dd>Fired when the completion is finished.</dd>
                </dl>
                This addon depends on styles
                from <code>addon/hint/show-hint.css</code>. Check
                out <a href="../demo/complete.html">the demo</a> for an
                example.
            </dd>

            <dt id="addon_javascript-hint"><a
                    href="../addon/hint/javascript-hint.js"><code>hint/javascript-hint.js</code></a></dt>
            <dd>Defines a simple hinting function for JavaScript
                (<code>CodeMirror.hint.javascript</code>) and CoffeeScript
                (<code>CodeMirror.hint.coffeescript</code>) code. This will
                simply use the JavaScript environment that the editor runs in as
                a source of information about objects and their properties.
            </dd>

            <dt id="addon_xml-hint"><a href="../addon/hint/xml-hint.js"><code>hint/xml-hint.js</code></a></dt>
            <dd>Defines <code>CodeMirror.hint.xml</code>, which produces
                hints for XML tagnames, attribute names, and attribute values,
                guided by a <code>schemaInfo</code> option (a property of the
                second argument passed to the hinting function, or the third
                argument passed to <code>CodeMirror.showHint</code>).<br>The
                schema info should be an object mapping tag names to information
                about these tags, with optionally a <code>"!top"</code> property
                containing a list of the names of valid top-level tags. The
                values of the properties should be objects with optional
                properties <code>children</code> (an array of valid child
                element names, omit to simply allow all tags to appear)
                and <code>attrs</code> (an object mapping attribute names
                to <code>null</code> for free-form attributes, and an array of
                valid values for restricted
                attributes).<br>The hint options accept an additional property:
                <dl>
                    <dt><code><strong>matchInMiddle</strong>: boolean</code></dt>
                    <dd>Determines whether typed characters are matched anywhere in
                        completions, not just at the beginning. Defaults to false.
                    </dd>
                </dl>
                <a href="../demo/xmlcomplete.html">Demo here</a>.
            </dd>

            <dt id="addon_html-hint"><a href="../addon/hint/html-hint.js"><code>hint/html-hint.js</code></a></dt>
            <dd>Provides schema info to
                the <a href="#addon_xml-hint">xml-hint</a> addon for HTML
                documents. Defines a schema
                object <code>CodeMirror.htmlSchema</code> that you can pass to
                as a <code>schemaInfo</code> option, and
                a <code>CodeMirror.hint.html</code> hinting function that
                automatically calls <code>CodeMirror.hint.xml</code> with this
                schema data. See
                the <a href="../demo/html5complete.html">demo</a>.
            </dd>

            <dt id="addon_css-hint"><a href="../addon/hint/css-hint.js"><code>hint/css-hint.js</code></a></dt>
            <dd>A hinting function for CSS, SCSS, or LESS code.
                Defines <code>CodeMirror.hint.css</code>.
            </dd>

            <dt id="addon_anyword-hint"><a href="../addon/hint/anyword-hint.js"><code>hint/anyword-hint.js</code></a>
            </dt>
            <dd>A very simple hinting function
                (<code>CodeMirror.hint.anyword</code>) that simply looks for
                words in the nearby code and completes to those. Takes two
                optional options, <code>word</code>, a regular expression that
                matches words (sequences of one or more character),
                and <code>range</code>, which defines how many lines the addon
                should scan when completing (defaults to 500).
            </dd>

            <dt id="addon_sql-hint"><a href="../addon/hint/sql-hint.js"><code>hint/sql-hint.js</code></a></dt>
            <dd>A simple SQL hinter. Defines <code>CodeMirror.hint.sql</code>.
                Takes two optional options, <code>tables</code>, a object with
                table names as keys and array of respective column names as values,
                and <code>defaultTable</code>, a string corresponding to a
                table name in <code>tables</code> for autocompletion.
            </dd>

            <dt id="addon_match-highlighter"><a href="../addon/search/match-highlighter.js"><code>search/match-highlighter.js</code></a>
            </dt>
            <dd>Adds a <code>highlightSelectionMatches</code> option that
                can be enabled to highlight all instances of a currently
                selected word. Can be set either to true or to an object
                containing the following options: <code>minChars</code>, for the
                minimum amount of selected characters that triggers a highlight
                (default 2), <code>style</code>, for the style to be used to
                highlight the matches (default <code>"matchhighlight"</code>,
                which will correspond to CSS
                class <code>cm-matchhighlight</code>), <code>trim</code>, which
                controls whether whitespace is trimmed from the selection,
                and <code>showToken</code> which can be set to <code>true</code>
                or to a regexp matching the characters that make up a word. When
                enabled, it causes the current word to be highlighted when
                nothing is selected (defaults to off).
                Demo <a href="../demo/matchhighlighter.html">here</a>.
            </dd>

            <dt id="addon_lint"><a href="../addon/lint/lint.js"><code>lint/lint.js</code></a></dt>
            <dd>Defines an interface component for showing linting warnings,
                with pluggable warning sources
                (see <a href="../addon/lint/html-lint.js"><code>html-lint.js</code></a>,
                <a href="../addon/lint/json-lint.js"><code>json-lint.js</code></a>,
                <a href="../addon/lint/javascript-lint.js"><code>javascript-lint.js</code></a>,
                <a href="../addon/lint/coffeescript-lint.js"><code>coffeescript-lint.js</code></a>,
                and <a href="../addon/lint/css-lint.js"><code>css-lint.js</code></a>
                in the same directory). Defines a <code>lint</code> option that
                can be set to an annotation source (for
                example <code>CodeMirror.lint.javascript</code>), to an options
                object (in which case the <code>getAnnotations</code> field is
                used as annotation source), or simply to <code>true</code>. When
                no annotation source is
                specified, <a href="#getHelper"><code>getHelper</code></a> with
                type <code>"lint"</code> is used to find an annotation function.
                An annotation source function should, when given a document
                string, an options object, and an editor instance, return an
                array of <code>{message, severity, from, to}</code> objects
                representing problems. When the function has
                an <code>async</code> property with a truthy value, it will be
                called with an additional second argument, which is a callback
                to pass the array to.
                The linting function can also return a promise, in that case the linter
                will only be executed when the promise resolves.
                By default, the linter will run (debounced) whenever the document is changed.
                You can pass a <code>lintOnChange: false</code> option to disable that.
                You can pass a <code>selfContain: true</code> option to render the tooltip inside the editor instance.
                Depends on <code>addon/lint/lint.css</code>. A demo can be
                found <a href="../demo/lint.html">here</a>.
            </dd>

            <dt id="addon_mark-selection"><a href="../addon/selection/mark-selection.js"><code>selection/mark-selection.js</code></a>
            </dt>
            <dd>Causes the selected text to be marked with the CSS class
                <code>CodeMirror-selectedtext</code> when the <code>styleSelectedText</code> option
                is enabled. Useful to change the colour of the selection (in addition to the background),
                like in <a href="../demo/markselection.html">this demo</a>.
            </dd>

            <dt id="addon_active-line"><a href="../addon/selection/active-line.js"><code>selection/active-line.js</code></a>
            </dt>
            <dd>Defines a <code>styleActiveLine</code> option that, when
                enabled, gives the wrapper of the line that contains the cursor
                the class <code>CodeMirror-activeline</code>, adds a background
                with the class <code>CodeMirror-activeline-background</code>,
                and adds the class <code>CodeMirror-activeline-gutter</code> to
                the line's gutter space is enabled. The option's value may be a
                boolean or an object specifying the following options:
                <dl>
                    <dt><code><strong>nonEmpty</strong>: bool</code></dt>
                    <dd>Controls whether single-line selections, or just cursor
                        selections, are styled. Defaults to false (only cursor
                        selections).
                    </dd>
                </dl>
                See the <a href="../demo/activeline.html">demo</a>.
            </dd>

            <dt id="addon_selection-pointer"><a href="../addon/selection/selection-pointer.js"><code>selection/selection-pointer.js</code></a>
            </dt>
            <dd>Defines a <code>selectionPointer</code> option which you can
                use to control the mouse cursor appearance when hovering over
                the selection. It can be set to a string,
                like <code>"pointer"</code>, or to true, in which case
                the <code>"default"</code> (arrow) cursor will be used. You can
                see a demo <a href="../mode/htmlmixed/index.html">here</a>.
            </dd>

            <dt id="addon_loadmode"><a href="../addon/mode/loadmode.js"><code>mode/loadmode.js</code></a></dt>
            <dd>Defines a <code>CodeMirror.requireMode(modename,
                callback)</code> function that will try to load a given mode and
                call the callback when it succeeded. You'll have to
                set <code>CodeMirror.modeURL</code> to a string that mode paths
                can be constructed from, for
                example <code>"mode/%N/%N.js"</code>—the <code>%N</code>'s will
                be replaced with the mode name. Also
                defines <code>CodeMirror.autoLoadMode(instance, mode)</code>,
                which will ensure the given mode is loaded and cause the given
                editor instance to refresh its mode when the loading
                succeeded. See the <a href="../demo/loadmode.html">demo</a>.
            </dd>

            <dt id="addon_meta"><a href="../mode/meta.js"><code>mode/meta.js</code></a></dt>
            <dd>Provides meta-information about all the modes in the
                distribution in a single file.
                Defines <code>CodeMirror.modeInfo</code>, an array of objects
                with <code>{name, mime, mode}</code> properties,
                where <code>name</code> is the human-readable
                name, <code>mime</code> the MIME type, and <code>mode</code> the
                name of the mode file that defines this MIME. There are optional
                properties <code>mimes</code>, which holds an array of MIME
                types for modes with multiple MIMEs associated,
                and <code>ext</code>, which holds an array of file extensions
                associated with this mode. Four convenience
                functions, <code>CodeMirror.findModeByMIME</code>,
                <code>CodeMirror.findModeByExtension</code>,
                <code>CodeMirror.findModeByFileName</code>
                and <code>CodeMirror.findModeByName</code> are provided, which
                return such an object given a MIME, extension, file name or mode name
                string. Note that, for historical reasons, this file resides in the
                top-level <code>mode</code> directory, not
                under <code>addon</code>. <a href="../demo/loadmode.html">Demo</a>.
            </dd>

            <dt id="addon_continuecomment"><a href="../addon/comment/continuecomment.js"><code>comment/continuecomment.js</code></a>
            </dt>
            <dd>Adds a <code>continueComments</code> option, which sets whether the
                editor will make the next line continue a comment when you press Enter
                inside a comment block. Can be set to a boolean to enable/disable this
                functionality. Set to a string, it will continue comments using a custom
                shortcut. Set to an object, it will use the <code>key</code> property for
                a custom shortcut and the boolean <code>continueLineComment</code>
                property to determine whether single-line comments should be continued
                (defaulting to <code>true</code>).
            </dd>

            <dt id="addon_placeholder"><a href="../addon/display/placeholder.js"><code>display/placeholder.js</code></a>
            </dt>
            <dd>Adds a <code>placeholder</code> option that can be used to
                make content appear in the editor when it is empty and not
                focused. It can hold either a string or a DOM node. Also gives
                the editor a <code>CodeMirror-empty</code> CSS class whenever it
                doesn't contain any text.
                See <a href="../demo/placeholder.html">the demo</a>.
            </dd>

            <dt id="addon_fullscreen"><a href="../addon/display/fullscreen.js"><code>display/fullscreen.js</code></a>
            </dt>
            <dd>Defines an option <code>fullScreen</code> that, when set
                to <code>true</code>, will make the editor full-screen (as in,
                taking up the whole browser window). Depends
                on <a href="../addon/display/fullscreen.css"><code>fullscreen.css</code></a>. <a
                        href="../demo/fullscreen.html">Demo
                    here</a>.
            </dd>

            <dt id="addon_autorefresh"><a href="../addon/display/autorefresh.js"><code>display/autorefresh.js</code></a>
            </dt>
            <dd>This addon can be useful when initializing an editor in a
                hidden DOM node, in cases where it is difficult to
                call <a href="#refresh"><code>refresh</code></a> when the editor
                becomes visible. It defines an option <code>autoRefresh</code>
                which you can set to true to ensure that, if the editor wasn't
                visible on initialization, it will be refreshed the first time
                it becomes visible. This is done by polling every 250
                milliseconds (you can pass a value like <code>{delay:
                    500}</code> as the option value to configure this). Note that
                this addon will only refresh the editor <em>once</em> when it
                first becomes visible, and won't take care of further restyling
                and resizing.
            </dd>

            <dt id="addon_simplescrollbars"><a href="../addon/scroll/simplescrollbars.js"><code>scroll/simplescrollbars.js</code></a>
            </dt>
            <dd>Defines two additional scrollbar
                models, <code>"simple"</code> and <code>"overlay"</code>
                (see <a href="../demo/simplescrollbars.html">demo</a>) that can
                be selected with
                the <a href="#option_scrollbarStyle"><code>scrollbarStyle</code></a>
                option. Depends
                on <a href="../addon/scroll/simplescrollbars.css"><code>simplescrollbars.css</code></a>,
                which can be further overridden to style your own
                scrollbars.
            </dd>

            <dt id="addon_annotatescrollbar"><a href="../addon/scroll/annotatescrollbar.js"><code>scroll/annotatescrollbar.js</code></a>
            </dt>
            <dd>Provides functionality for showing markers on the scrollbar
                to call out certain parts of the document. Adds a
                method <code>annotateScrollbar</code> to editor instances that
                can be called, with a CSS class name as argument, to create a
                set of annotations. The method returns an object
                whose <code>update</code> method can be called with a sorted array
                of <code>{from: Pos, to: Pos}</code> objects marking the ranges
                to be highlighted. To detach the annotations, call the
                object's <code>clear</code> method.
            </dd>

            <dt id="addon_rulers"><a href="../addon/display/rulers.js"><code>display/rulers.js</code></a></dt>
            <dd>Adds a <code>rulers</code> option, which can be used to show
                one or more vertical rulers in the editor. The option, if
                defined, should be given an array of <code>{column [, className,
                    color, lineStyle, width]}</code> objects or numbers (which
                indicate a column). The ruler will be displayed at the column
                indicated by the number or the <code>column</code> property.
                The <code>className</code> property can be used to assign a
                custom style to a ruler. <a href="../demo/rulers.html">Demo
                    here</a>.
            </dd>

            <dt id="addon_panel"><a href="../addon/display/panel.js"><code>display/panel.js</code></a></dt>
            <dd>Defines an <code>addPanel</code> method for CodeMirror
                instances, which places a DOM node above or below an editor, and
                shrinks the editor to make room for the node. The method takes
                as first argument as DOM node, and as second an optional options
                object. The <code>Panel</code> object returned by this method
                has a <code>clear</code> method that is used to remove the
                panel, and a <code>changed</code> method that can be used to
                notify the addon when the size of the panel's DOM node has
                changed.<br/>
                The method accepts the following options:
                <dl>
                    <dt><code><strong>position</strong>: string</code></dt>
                    <dd>Controls the position of the newly added panel. The
                        following values are recognized:
                        <dl>
                            <dt><code><strong>top</strong> (default)</code></dt>
                            <dd>Adds the panel at the very top.</dd>
                            <dt><code><strong>after-top</strong></code></dt>
                            <dd>Adds the panel at the bottom of the top panels.</dd>
                            <dt><code><strong>bottom</strong></code></dt>
                            <dd>Adds the panel at the very bottom.</dd>
                            <dt><code><strong>before-bottom</strong></code></dt>
                            <dd>Adds the panel at the top of the bottom panels.</dd>
                        </dl>
                    </dd>
                    <dt><code><strong>before</strong>: Panel</code></dt>
                    <dd>The new panel will be added before the given panel.</dd>
                    <dt><code><strong>after</strong>: Panel</code></dt>
                    <dd>The new panel will be added after the given panel.</dd>
                    <dt><code><strong>replace</strong>: Panel</code></dt>
                    <dd>The new panel will replace the given panel.</dd>
                    <dt><code><strong>stable</strong>: bool</code></dt>
                    <dd>Whether to scroll the editor to keep the text's vertical
                        position stable, when adding a panel above it. Defaults to false.
                    </dd>
                </dl>
                When using the <code>after</code>, <code>before</code> or <code>replace</code> options,
                if the panel doesn't exists or has been removed,
                the value of the <code>position</code> option will be used as a fallback.
                <br>
                A demo of the addon is available <a href="../demo/panel.html">here</a>.
            </dd>

            <dt id="addon_hardwrap"><a href="../addon/wrap/hardwrap.js"><code>wrap/hardwrap.js</code></a></dt>
            <dd>Addon to perform hard line wrapping/breaking for paragraphs
                of text. Adds these methods to editor instances:
                <dl>
                    <dt><code><strong>wrapParagraph</strong>(?pos: {line, ch}, ?options: object)</code></dt>
                    <dd>Wraps the paragraph at the given position.
                        If <code>pos</code> is not given, it defaults to the cursor
                        position.
                    </dd>
                    <dt><code><strong>wrapRange</strong>(from: {line, ch}, to: {line, ch}, ?options: object)</code></dt>
                    <dd>Wraps the given range as one big paragraph.</dd>
                    <dt><code><strong>wrapParagraphsInRange</strong>(from: {line, ch}, to: {line, ch}, ?options: object)</code>
                    </dt>
                    <dd>Wraps the paragraphs in (and overlapping with) the
                        given range individually.
                    </dd>
                </dl>
                The following options are recognized:
                <dl>
                    <dt><code><strong>paragraphStart</strong>, <strong>paragraphEnd</strong>: RegExp</code></dt>
                    <dd>Blank lines are always considered paragraph boundaries.
                        These options can be used to specify a pattern that causes
                        lines to be considered the start or end of a paragraph.
                    </dd>
                    <dt><code><strong>column</strong>: number</code></dt>
                    <dd>The column to wrap at. Defaults to 80.</dd>
                    <dt><code><strong>wrapOn</strong>: RegExp</code></dt>
                    <dd>A regular expression that matches only those
                        two-character strings that allow wrapping. By default, the
                        addon wraps on whitespace and after dash characters.
                    </dd>
                    <dt><code><strong>killTrailingSpace</strong>: boolean</code></dt>
                    <dd>Whether trailing space caused by wrapping should be
                        preserved, or deleted. Defaults to true.
                    </dd>
                </dl>
                A demo of the addon is available <a href="../demo/hardwrap.html">here</a>.
            </dd>

            <dt id="addon_merge"><a href="../addon/merge/merge.js"><code>merge/merge.js</code></a></dt>
            <dd>Implements an interface for merging changes, using either a
                2-way or a 3-way view. The <code>CodeMirror.MergeView</code>
                constructor takes arguments similar to
                the <a href="#CodeMirror"><code>CodeMirror</code></a>
                constructor, first a node to append the interface to, and then
                an options object. Options are passed through to the editors
                inside the view. These extra options are recognized:
                <dl>
                    <dt><code><strong>origLeft</strong></code> and <code><strong>origRight</strong>: string</code></dt>
                    <dd>If given these provide original versions of the
                        document, which will be shown to the left and right of the
                        editor in non-editable CodeMirror instances. The merge
                        interface will highlight changes between the editable
                        document and the original(s). To create a 2-way (as opposed
                        to 3-way) merge view, provide only one of them.
                    </dd>
                    <dt><code><strong>revertButtons</strong>: boolean</code></dt>
                    <dd>Determines whether buttons that allow the user to revert
                        changes are shown. Defaults to true.
                    </dd>
                    <dt><code><strong>revertChunk</strong>: fn(mv: MergeView, from: CodeMirror, fromStart: Pos, fromEnd:
                        Pos, to: CodeMirror, toStart: Pos, toEnd: Pos)</code></dt>
                    <dd>Can be used to define custom behavior when the user
                        reverts a changed chunk.
                    </dd>
                    <dt><code><strong>connect</strong>: string</code></dt>
                    <dd>Sets the style used to connect changed chunks of code.
                        By default, connectors are drawn. When this is set
                        to <code>"align"</code>, the smaller chunk is padded to
                        align with the bigger chunk instead.
                    </dd>
                    <dt><code><strong>collapseIdentical</strong>: boolean|number</code></dt>
                    <dd>When true (default is false), stretches of unchanged
                        text will be collapsed. When a number is given, this
                        indicates the amount of lines to leave visible around such
                        stretches (which defaults to 2).
                    </dd>
                    <dt><code><strong>allowEditingOriginals</strong>: boolean</code></dt>
                    <dd>Determines whether the original editor allows editing.
                        Defaults to false.
                    </dd>
                    <dt><code><strong>showDifferences</strong>: boolean</code></dt>
                    <dd>When true (the default), changed pieces of text are
                        highlighted.
                    </dd>
                    <dt><code><strong>chunkClassLocation</strong>: string|Array</code></dt>
                    <dd>By default the chunk highlights are added
                        using <a href="#addLineClass"><code>addLineClass</code></a>
                        with "background". Override this to customize it to be any
                        valid `where` parameter or an Array of valid `where`
                        parameters.
                    </dd>
                </dl>
                The addon also defines commands <code>"goNextDiff"</code>
                and <code>"goPrevDiff"</code> to quickly jump to the next
                changed chunk. <a href="../demo/merge.html">Demo
                    here</a>.
            </dd>

            <dt id="addon_tern"><a href="../addon/tern/tern.js"><code>tern/tern.js</code></a></dt>
            <dd>Provides integration with
                the <a href="https://ternjs.net">Tern</a> JavaScript analysis
                engine, for completion, definition finding, and minor
                refactoring help. See the <a href="../demo/tern.html">demo</a>
                for a very simple integration. For more involved scenarios, see
                the comments at the top of
                the <a href="../addon/tern/tern.js">addon</a> and the
                implementation of the
                (multi-file) <a href="https://ternjs.net/doc/demo/index.html">demonstration
                    on the Tern website</a>.
            </dd>
        </dl>
    </section>

    <section id=modeapi>
        <h2>Writing CodeMirror Modes</h2>

        <p>Modes typically consist of a single JavaScript file. This file
            defines, in the simplest case, a lexer (tokenizer) for your
            language—a function that takes a character stream as input,
            advances it past a token, and returns a style for that token. More
            advanced modes can also handle indentation for the language.</p>

        <p>This section describes the low-level mode interface. Many modes
            are written directly against this, since it offers a lot of
            control, but for a quick mode definition, you might want to use
            the <a href="../demo/simplemode.html">simple mode addon</a>.</p>

        <p id="defineMode">The mode script should
            call <code><strong>CodeMirror.defineMode</strong></code> to
            register itself with CodeMirror. This function takes two
            arguments. The first should be the name of the mode, for which you
            should use a lowercase string, preferably one that is also the
            name of the files that define the mode (i.e. <code>"xml"</code> is
            defined in <code>xml.js</code>). The second argument should be a
            function that, given a CodeMirror configuration object (the thing
            passed to the <code>CodeMirror</code> function) and an optional
            mode configuration object (as in
            the <a href="#option_mode"><code>mode</code></a> option), returns
            a mode object.</p>

        <p>Typically, you should use this second argument
            to <code>defineMode</code> as your module scope function (modes
            should not leak anything into the global scope!), i.e. write your
            whole mode inside this function.</p>

        <p>The main responsibility of a mode script is <em>parsing</em>
            the content of the editor. Depending on the language and the
            amount of functionality desired, this can be done in really easy
            or extremely complicated ways. Some parsers can be stateless,
            meaning that they look at one element (<em>token</em>) of the code
            at a time, with no memory of what came before. Most, however, will
            need to remember something. This is done by using a <em>state
                object</em>, which is an object that is always passed when
            reading a token, and which can be mutated by the tokenizer.</p>

        <p id="startState">Modes that use a state must define
            a <code><strong>startState</strong></code> method on their mode
            object. This is a function of no arguments that produces a state
            object to be used at the start of a document.</p>

        <p id="token">The most important part of a mode object is
            its <code><strong>token</strong>(stream, state)</code> method. All
            modes must define this method. It should read one token from the
            stream it is given as an argument, optionally update its state,
            and return a style string, or <code>null</code> for tokens that do
            not have to be styled. For your styles, you are encouraged to use
            the 'standard' names defined in the themes (without
            the <code>cm-</code> prefix). If that fails, it is also possible
            to come up with your own and write your own CSS theme file.
        <p>

        <p id="token_style_line">A typical token string would
            be <code>"variable"</code> or <code>"comment"</code>. Multiple
            styles can be returned (separated by spaces), for
            example <code>"string error"</code> for a thing that looks like a
            string but is invalid somehow (say, missing its closing quote).
            When a style is prefixed by <code>"line-"</code>
            or <code>"line-background-"</code>, the style will be applied to
            the whole line, analogous to what
            the <a href="#addLineClass"><code>addLineClass</code></a> method
            does—styling the <code>"text"</code> in the simple case, and
            the <code>"background"</code> element
            when <code>"line-background-"</code> is prefixed.</p>

        <p id="StringStream">The stream object that's passed
            to <code>token</code> encapsulates a line of code (tokens may
            never span lines) and our current position in that line. It has
            the following API:</p>

        <dl>
            <dt><code><strong>eol</strong>() → boolean</code></dt>
            <dd>Returns true only if the stream is at the end of the
                line.
            </dd>
            <dt><code><strong>sol</strong>() → boolean</code></dt>
            <dd>Returns true only if the stream is at the start of the
                line.
            </dd>

            <dt><code><strong>peek</strong>() → string</code></dt>
            <dd>Returns the next character in the stream without advancing
                it. Will return a <code>null</code> at the end of the
                line.
            </dd>
            <dt><code><strong>next</strong>() → string</code></dt>
            <dd>Returns the next character in the stream and advances it.
                Also returns <code>null</code> when no more characters are
                available.
            </dd>

            <dt><code><strong>eat</strong>(match: string|regexp|function(char: string) → boolean) → string</code></dt>
            <dd><code>match</code> can be a character, a regular expression,
                or a function that takes a character and returns a boolean. If
                the next character in the stream 'matches' the given argument,
                it is consumed and returned. Otherwise, <code>undefined</code>
                is returned.
            </dd>
            <dt><code><strong>eatWhile</strong>(match: string|regexp|function(char: string) → boolean) → boolean</code>
            </dt>
            <dd>Repeatedly calls <code>eat</code> with the given argument,
                until it fails. Returns true if any characters were eaten.
            </dd>
            <dt><code><strong>eatSpace</strong>() → boolean</code></dt>
            <dd>Shortcut for <code>eatWhile</code> when matching
                white-space.
            </dd>
            <dt><code><strong>skipToEnd</strong>()</code></dt>
            <dd>Moves the position to the end of the line.</dd>
            <dt><code><strong>skipTo</strong>(str: string) → boolean</code></dt>
            <dd>Skips to the start of the next occurrence of the given string, if
                found on the current line (doesn't advance the stream if the
                string does not occur on the line). Returns true if the
                string was found.
            </dd>
            <dt><code><strong>match</strong>(pattern: string, ?consume: boolean, ?caseFold: boolean) → boolean</code>
            </dt>
            <dt><code><strong>match</strong>(pattern: regexp, ?consume: boolean) → array&lt;string&gt;</code></dt>
            <dd>Act like a
                multi-character <code>eat</code>—if <code>consume</code> is true
                or not given—or a look-ahead that doesn't update the stream
                position—if it is false. <code>pattern</code> can be either a
                string or a regular expression starting with <code>^</code>.
                When it is a string, <code>caseFold</code> can be set to true to
                make the match case-insensitive. When successfully matching a
                regular expression, the returned value will be the array
                returned by <code>match</code>, in case you need to extract
                matched groups.
            </dd>

            <dt><code><strong>backUp</strong>(n: integer)</code></dt>
            <dd>Backs up the stream <code>n</code> characters. Backing it up
                further than the start of the current token will cause things to
                break, so be careful.
            </dd>
            <dt><code><strong>column</strong>() → integer</code></dt>
            <dd>Returns the column (taking into account tabs) at which the
                current token starts.
            </dd>
            <dt><code><strong>indentation</strong>() → integer</code></dt>
            <dd>Tells you how far the current line has been indented, in
                spaces. Corrects for tab characters.
            </dd>

            <dt><code><strong>current</strong>() → string</code></dt>
            <dd>Get the string between the start of the current token and
                the current stream position.
            </dd>

            <dt><code><strong>lookAhead</strong>(n: number) → ?string</code></dt>
            <dd>Get the line <code>n</code> (&gt;0) lines after the current
                one, in order to scan ahead across line boundaries. Note that
                you want to do this carefully, since looking far ahead will make
                mode state caching much less effective.
            </dd>

            <dt id="baseToken"><code><strong>baseToken</strong>() → ?{type: ?string, size: number}</code></dt>
            <dd>Modes added
                through <a href="#addOverlay"><code>addOverlay</code></a>
                (and <em>only</em> such modes) can use this method to inspect
                the current token produced by the underlying mode.
            </dd>
        </dl>

        <p id="blankLine">By default, blank lines are simply skipped when
            tokenizing a document. For languages that have significant blank
            lines, you can define
            a <code><strong>blankLine</strong>(state)</code> method on your
            mode that will get called whenever a blank line is passed over, so
            that it can update the parser state.</p>

        <p id="copyState">Because state object are mutated, and CodeMirror
            needs to keep valid versions of a state around so that it can
            restart a parse at any line, copies must be made of state objects.
            The default algorithm used is that a new state object is created,
            which gets all the properties of the old object. Any properties
            which hold arrays get a copy of these arrays (since arrays tend to
            be used as mutable stacks). When this is not correct, for example
            because a mode mutates non-array properties of its state object, a
            mode object should define
            a <code><strong>copyState</strong></code> method, which is given a
            state and should return a safe copy of that state.</p>

        <p id="indent">If you want your mode to provide smart indentation
            (through the <a href="#indentLine"><code>indentLine</code></a>
            method and the <code>indentAuto</code>
            and <code>newlineAndIndent</code> commands, to which keys can be
            <a href="#option_extraKeys">bound</a>), you must define
            an <code><strong>indent</strong>(state, textAfter)</code> method
            on your mode object.</p>

        <p>The indentation method should inspect the given state object,
            and optionally the <code>textAfter</code> string, which contains
            the text on the line that is being indented, and return an
            integer, the amount of spaces to indent. It should usually take
            the <a href="#option_indentUnit"><code>indentUnit</code></a>
            option into account. An indentation method may
            return <code>CodeMirror.Pass</code> to indicate that it
            could not come up with a precise indentation.</p>

        <p id="mode_comment">To work well with
            the <a href="#addon_comment">commenting addon</a>, a mode may
            define <code><strong>lineComment</strong></code> (string that
            starts a line
            comment), <code><strong>blockCommentStart</strong></code>, <code><strong>blockCommentEnd</strong></code>
            (strings that start and end block comments),
            and <code>blockCommentLead</code> (a string to put at the start of
            continued lines in a block comment). All of these are
            optional.</p>

        <p id="electricChars">Finally, a mode may define either
            an <code>electricChars</code> or an <code>electricInput</code>
            property, which are used to automatically reindent the line when
            certain patterns are typed and
            the <a href="#option_electricChars"><code>electricChars</code></a>
            option is enabled. <code>electricChars</code> may be a string, and
            will trigger a reindent whenever one of the characters in that
            string are typed. Often, it is more appropriate to
            use <code>electricInput</code>, which should hold a regular
            expression, and will trigger indentation when the part of the
            line <em>before</em> the cursor matches the expression. It should
            usually end with a <code>$</code> character, so that it only
            matches when the indentation-changing pattern was just typed, not when something was
            typed after the pattern.</p>

        <p>So, to summarize, a mode <em>must</em> provide
            a <code>token</code> method, and it <em>may</em>
            provide <code>startState</code>, <code>copyState</code>,
            and <code>indent</code> methods. For an example of a trivial mode,
            see the <a href="../mode/diff/diff.js">diff mode</a>, for a more
            involved example, see the <a href="../mode/clike/clike.js">C-like
                mode</a>.</p>

        <p>Sometimes, it is useful for modes to <em>nest</em>—to have one
            mode delegate work to another mode. An example of this kind of
            mode is the <a href="../mode/htmlmixed/htmlmixed.js">mixed-mode HTML
                mode</a>. To implement such nesting, it is usually necessary to
            create mode objects and copy states yourself. To create a mode
            object, there are <code>CodeMirror.getMode(options,
                parserConfig)</code>, where the first argument is a configuration
            object as passed to the mode constructor function, and the second
            argument is a mode specification as in
            the <a href="#option_mode"><code>mode</code></a> option. To copy a
            state object, call <code>CodeMirror.copyState(mode, state)</code>,
            where <code>mode</code> is the mode that created the given
            state.</p>

        <p id="innerMode">In a nested mode, it is recommended to add an
            extra method, <code><strong>innerMode</strong></code> which, given
            a state object, returns a <code>{state, mode}</code> object with
            the inner mode and its state for the current position. These are
            used by utility scripts such as the <a href="#addon_closetag">tag
                closer</a> to get context information. Use
            the <code>CodeMirror.innerMode</code> helper function to, starting
            from a mode and a state, recursively walk down to the innermost
            mode and state.</p>

        <p>To make indentation work properly in a nested parser, it is
            advisable to give the <code>startState</code> method of modes that
            are intended to be nested an optional argument that provides the
            base indentation for the block of code. The JavaScript and CSS
            parser do this, for example, to allow JavaScript and CSS code
            inside the mixed-mode HTML mode to be properly indented.</p>

        <p id="defineMIME">It is possible, and encouraged, to associate
            your mode, or a certain configuration of your mode, with
            a <a href="http://en.wikipedia.org/wiki/MIME">MIME</a> type. For
            example, the JavaScript mode associates itself
            with <code>text/javascript</code>, and its JSON variant
            with <code>application/json</code>. To do this,
            call <code><strong>CodeMirror.defineMIME</strong>(mime,
                modeSpec)</code>, where <code>modeSpec</code> can be a string or
            object specifying a mode, as in
            the <a href="#option_mode"><code>mode</code></a> option.</p>

        <p>If a mode specification wants to add some properties to the
            resulting mode object, typically for use
            with <a href="#getHelpers"><code>getHelpers</code></a>, it may
            contain a <code>modeProps</code> property, which holds an object.
            This object's properties will be copied to the actual mode
            object.</p>

        <p id="extendMode">Sometimes, it is useful to add or override mode
            object properties from external code.
            The <code><strong>CodeMirror.extendMode</strong></code> function
            can be used to add properties to mode objects produced for a
            specific mode. Its first argument is the name of the mode, its
            second an object that specifies the properties that should be
            added. This is mostly useful to add utilities that can later be
            looked up through <a href="#getMode"><code>getMode</code></a>.</p>
    </section>

    <section id="vimapi">
        <h2>VIM Mode API</h2>

        <p>CodeMirror has a robust VIM mode that attempts to faithfully
            emulate VIM's most useful features. It can be enabled by
            including <a href="../keymap/vim.js"><code>keymap/vim.js</code>
            </a> and setting the <code>keyMap</code> option to
            <code>"vim"</code>.</p>

        <h3 id="vimapi_configuration">Configuration</h3>

        <p>VIM mode accepts configuration options for customizing
            behavior at run time. These methods can be called at any time
            and will affect all existing CodeMirror instances unless
            specified otherwise. The methods are exposed on the
            <code><strong>CodeMirror.Vim</strong></code> object.</p>

        <dl>
            <dt id="vimapi_setOption"><code><strong>setOption(name: string, value: any, ?cm: CodeMirror, ?cfg:
                object)</strong></code></dt>
            <dd>Sets the value of a VIM option. <code>name</code> should
                be the name of an option. If <code>cfg.scope</code> is not set
                and <code>cm</code> is provided, then sets the global and
                instance values of the option. Otherwise, sets either the
                global or instance value of the option depending on whether
                <code>cfg.scope</code> is <code>global</code> or
                <code>local</code>.
            </dd>
            <dt id="vimapi_getOption"><code><strong>getOption(name: string, ?cm: CodeMirror: ?cfg:
                object)</strong></code></dt>
            <dd>Gets the current value of a VIM option. If
                <code>cfg.scope</code> is not set and <code>cm</code> is
                provided, then gets the instance value of the option, falling
                back to the global value if not set. If <code>cfg.scope</code> is provided, then gets the
                <code>global</code> or
                <code>local</code> value without checking the other.
            </dd>

            <dt id="vimapi_map"><code><strong>map(lhs: string, rhs: string, ?context: string)</strong></code></dt>
            <dd>Maps a key sequence to another key sequence. Implements
                VIM's <code>:map</code> command. To map ; to : in VIM would be
                <code><strong>:map ; :</strong></code>. That would translate to
                <code><strong>CodeMirror.Vim.map(';', ':');</strong></code>.
                The <code>context</code> can be <code>normal</code>,
                <code>visual</code>, or <code>insert</code>, which correspond
                to <code>:nmap</code>, <code>:vmap</code>, and
                <code>:imap</code>
                respectively.
            </dd>

            <dt id="vimapi_mapCommand"><code><strong>mapCommand(keys: string, type: string, name: string, ?args: object,
                ?extra: object)</strong></code></dt>
            <dd>Maps a key sequence to a <code>motion</code>,
                <code>operator</code>, or <code>action</code> type command.
                The args object is passed through to the command when it is
                invoked by the provided key sequence.
                <code>extras.context</code> can be <code>normal</code>,
                <code>visual</code>, or <code>insert</code>, to map the key
                sequence only in the corresponding mode.
                <code>extras.isEdit</code> is applicable only to actions,
                determining whether it is recorded for replay for the
                <code>.</code> single-repeat command.
        </dl>

        <h3 id="vimapi_extending">Extending VIM</h3>

        <p>CodeMirror's VIM mode implements a large subset of VIM's core
            editing functionality. But since there's always more to be
            desired, there is a set of APIs for extending VIM's
            functionality. As with the configuration API, the methods are
            exposed on <code><strong>CodeMirror.Vim</strong></code> and may
            be called at any time.</p>

        <dl>
            <dt id="vimapi_defineOption"><code><strong>defineOption(name: string, default: any, type: string, ?aliases:
                array&lt;string&gt;, ?callback: function (?value: any, ?cm: CodeMirror) → ?any)</strong></code></dt>
            <dd>Defines a VIM style option and makes it available to the
                <code>:set</code> command. Type can be <code>boolean</code> or
                <code>string</code>, used for validation and by
                <code>:set</code> to determine which syntax to accept. If a
                <code>callback</code> is passed in, VIM does not store the value of the
                option itself, but instead uses the callback as a setter/getter. If the
                first argument to the callback is <code>undefined</code>, then the
                callback should return the value of the option. Otherwise, it should set
                instead. Since VIM options have global and instance values, whether a
                <code>CodeMirror</code> instance is passed in denotes whether the global
                or local value should be used. Consequently, it's possible for the
                callback to be called twice for a single <code>setOption</code> or
                <code>getOption</code> call. Note that right now, VIM does not support
                defining buffer-local options that do not have global values. If an
                option should not have a global value, either always ignore the
                <code>cm</code> parameter in the callback, or always pass in a
                <code>cfg.scope</code> to <code>setOption</code> and
                <code>getOption</code>.
            </dd>

            <dt id="vimapi_defineMotion"><code><strong>defineMotion(name: string, fn: function(cm: CodeMirror, head:
                {line, ch}, ?motionArgs: object}) → {line, ch})</strong></code></dt>
            <dd>Defines a motion command for VIM. The motion should return
                the desired result position of the cursor. <code>head</code>
                is the current position of the cursor. It can differ from
                <code>cm.getCursor('head')</code> if VIM is in visual mode.
                <code>motionArgs</code> is the object passed into
                <strong><code>mapCommand()</code></strong>.
            </dd>

            <dt id="vimapi_defineOperator"><strong><code>defineOperator(name: string, fn: function(cm: CodeMirror,
                ?operatorArgs: object, ranges: array&lt;{anchor, head}&gt;) → ?{line, ch})</code></strong></dt>
            <dd>Defines an operator command, similar to <strong><code>
                defineMotion</code></strong>. <code>ranges</code> is the range
                of text the operator should operate on. If the cursor should
                be set to a certain position after the operation finishes, it
                can return a cursor object.
            </dd>

            <dt id="vimapi_defineActon"><strong><code>defineAction(name: string, fn: function(cm: CodeMirror,
                ?actionArgs: object))</code></strong></dt>
            <dd>Defines an action command, similar to
                <strong><code>defineMotion</code></strong>. Action commands
                can have arbitrary behavior, making them more flexible than
                motions and operators, at the loss of orthogonality.
            </dd>

            <dt id="vimapi_defineEx"><strong><code>defineEx(name: string, ?prefix: string, fn: function(cm: CodeMirror,
                ?params: object))</code></strong></dt>
            <dd>Defines an Ex command, and maps it to <code>:name</code>.
                If a prefix is provided, it, and any prefixed substring of the
                <code>name</code> beginning with the <code>prefix</code> can
                be used to invoke the command. If the <code>prefix</code> is
                falsy, then <code>name</code> is used as the prefix. <code>
                    params.argString</code> contains the part of the prompted
                string after the command name. <code>params.args</code> is
                <code>params.argString</code> split by whitespace. If the
                command was prefixed with a
                <code><strong><a href="http://vimdoc.sourceforge.net/htmldoc/cmdline.html#cmdline-ranges">line range</a></strong></code>,
                <code>params.line</code> and <code>params.lineEnd</code> will
                be set.
        </dl>

    </section>

</article>

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